Modular LED lighting systems

ABSTRACT

In accordance with various embodiments, a modular lighting system features multiple light panels each having multiple light-emitting elements thereon, as well as connectors for electrically and mechanically interconnecting the light panels.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 14/713,014, filed May 15, 2015, which is a continuation of U.S. patent application Ser. No. 14/699,149, filed Apr. 29, 2015, which claims the benefit of and priority to U.S. Provisional Patent Application No. 61/985,759, filed Apr. 29, 2014, and U.S. Provisional Patent Application No. 62/029,151, filed Jul. 25, 2014, the entire disclosure of each of which is hereby incorporated herein by reference.

FIELD OF THE INVENTION

In various embodiments, the present invention generally relates to electronic devices, and more specifically to array-based electronic devices.

BACKGROUND

Solid-state lighting is an attractive alternative to incandescent and fluorescent lighting systems for backlighting of translucent panels or materials and signs because of its relatively higher efficiency, robustness, and long life. A number of LED-based backlighting systems have been used, but these generally suffer from one or more deficiencies. It is often desirable to have the thickness of the panel or sign as small as possible, for example to fit within a restricted space, to provide a thin visual perspective, or to reduce cost. Current LED systems generally include LEDs that are operated at relatively high current, resulting in very bright light sources that must be mixed and diffused to provide even and low-glare illumination of the panel or sign. For systems having LEDs spaced several inches or more apart, this may result in an undesirably large spacing between the LEDs and the diffuser. The diffuser reduces the efficiency, and as the LEDs become brighter, more diffusion, with concomitant decreasing efficiency, is required to achieve a homogeneous luminance across the panel or sign. Furthermore, such systems often require relatively large heat sinks or thermal management systems, which also take up space and may require suitable ventilation, for example passive ventilation or active ventilation such as fans, to prevent deleterious heat buildup. These issues typically lead to undesirably large, thick, and potentially complicated lighting systems.

In addition, many applications for backlighting and illuminated panels and signs require custom sizing to fit in a particular location. Systems consisting of relatively few high-brightness LEDs on rigid circuit boards or systems employing edge-lit panels may be difficult to use cost-effectively in a wide range of installations, e.g., installations requiring size customization while maintaining high illumination uniformity and high efficiency.

Accordingly, there is a need for solutions that provide LED-based lighting systems having a thin form factor with improved uniformity, high efficiency, and which are simple to install.

SUMMARY

Embodiments of the present invention relate to illumination systems based on flexible light sheets and that incorporate additional functionality that enables various different mechanical mounting and electrical and/or mechanical joining techniques. For example, illumination systems in accordance with embodiments of the invention incorporate rigid or semi-rigid mounting frames that may also provide electrical connectivity. In various embodiments, the illumination systems are modular and feature connection mechanisms (e.g., snap connectors) that mechanically and electrically interconnect individual light panels or light sheets together and/or to power-distribution systems and/or to mounting rails.

Additional details of lighting systems in accordance with embodiments of the present invention appear within U.S. patent application Ser. No. 13/799,807, filed Mar. 13, 2013 (the '807 application), and U.S. patent application Ser. No. 13/748,864, filed Jan. 24, 2013 (the '864 application), the entire disclosure of each of which is incorporated by reference herein.

In an aspect, embodiments of the invention feature a lighting system that includes or consists essentially of a first light panel and a second light panel. The first light panel includes or consists essentially of a first substrate, first and second spaced-apart power conductors disposed on the first substrate, a plurality of first light-emitting elements disposed on the first substrate and electrically connected to the first and second power conductors, a first snap connector electrically connected to the first power conductor, and a second snap connector electrically connected to the second power conductor. The second light panel includes or consists essentially of a second substrate, third and fourth spaced-apart power conductors disposed on the second substrate, a plurality of second light-emitting elements disposed on the second substrate and electrically connected to the third and fourth power conductors, a third snap connector electrically connected to the third power conductor, and a fourth snap connector electrically connected to the fourth power conductor. The first snap connector is configured for connection to the third snap connector, thereby electrically coupling the first power conductor to the third power conductor. The second snap connector is configured for connection to the fourth snap connector, thereby electrically coupling the second power conductor to the fourth power conductor.

Embodiments of the invention may include one or more of the following in any of a variety of combinations. The third and/or fourth snap connectors may be disposed on one or more tabs extending from the second substrate. The third and/or fourth snap connectors may be disposed on a folded-over portion of one of the tabs extending from the second substrate. The first light panel may include a fifth snap connector electrically connected to the first power conductor, and/or a sixth snap connector electrically connected to the second power conductor. The fifth and/or sixth snap connectors may be disposed on one or more tabs extending from the first substrate. The second light panel may include a fifth snap connector and electrically connected to the third power conductor, and/or a sixth snap connector and electrically connected to the fourth power conductor. The fifth and/or sixth snap connectors may be disposed on one or more tabs extending from the second substrate.

The lighting system may include a power distribution bus. The power distribution bus may include or consist essentially of first and second power distribution lines, a seventh snap connector electrically connected to the first power distribution line, and an eighth snap connector electrically connected to the second power distribution line. The seventh snap connector may be configured for connection to the fifth snap connector, thereby electrically coupling the third power conductor to the first power distribution line. The eighth snap connector may be configured for connection to the sixth snap connector, thereby electrically coupling the fourth power conductor to the second power distribution line. The lighting system may include first and second jumpers. The first jumper may include or consist essentially of a first jumper connector configured for connection to the fifth snap connector and a second jumper connector configured for connection to the seventh snap connector, thereby electrically coupling the third power conductor to the first power distribution line. The second jumper may include or consist essentially of a third jumper connector configured for connection to the sixth snap connector and a fourth jumper connector configured for connection to the eighth snap connector, thereby electrically coupling the fourth power conductor to the second power distribution line. The first, second, third, and/or fourth snap connectors may each include or consist essentially of at least a portion of a 9V battery connector. The first, second, third, and/or fourth snap connectors may each include or consist essentially of a pin connector (e.g., an electrically conductive pin and/or an electrically conductive cap or ring shaped and sized to fit over the pin and make electrical contact thereto).

When the first snap connector is connected to the third snap connector and the second snap connector is connected to the fourth snap connector, over the first and second substrates, the first and second light-emitting elements may be spaced apart at a constant pitch, and the pitch may be maintained between the first and second substrates. The first substrate may include a plurality of first conductive traces thereon. The plurality of first light-emitting elements may be spaced apart and interconnected, via the plurality of first conductive traces, into one or more first light-emitting strings. Each first light-emitting string may have (i) a first end electrically connected to the first power conductor and/or (ii) a second end electrically connected to the second power conductor. One or more first control elements may be configured to control current to one or more of the first light-emitting strings. The one or more first control elements may be disposed on the first substrate and/or the second substrate. The one or more first control elements may each be electrically coupled to at least one first light-emitting string. The first substrate may be separable, via a cut spanning the first and second power conductors and not crossing a first light-emitting string, into two partial substrates each including or consisting essentially of (i) one or more first light-emitting strings, and (ii) portions of the first and second power conductors configured to supply power to and thereby illuminate the one or more first light-emitting strings of the partial substrate.

Along each first light-emitting string, a first pitch at which the first light-emitting elements are spaced may be substantially constant. The one or more first light-emitting strings may include or consist essentially of a plurality of first light-emitting strings. Over the first substrate, the first light-emitting elements may be spaced apart at the first pitch, and the first pitch may be maintained between first light-emitting elements of different ones of the first light-emitting strings. When the first snap connector is connected to the third snap connector and the second snap connector is connected to the fourth snap connector, over the first and second substrates, the first and second light-emitting elements may be spaced apart at the first pitch, and the first pitch may be maintained between the first and second substrates. The lighting system may include a third light panel and a fourth light panel. The third light panel may include or consist essentially of a third substrate, fifth and sixth spaced-apart power conductors disposed on the third substrate, a plurality of third light-emitting elements disposed on the third substrate and electrically connected to the fifth and sixth power conductors, a fifth snap connector electrically connected to the fifth power conductor, and a sixth snap connector electrically connected to the sixth power conductor. The fourth light panel may include or consist essentially of a fourth substrate, seventh and eighth spaced-apart power conductors disposed on the fourth substrate, a plurality of fourth light-emitting elements disposed on the fourth substrate and electrically connected to the seventh and eighth power conductors, a seventh snap connector electrically connected to the seventh power conductor, and an eighth snap connector electrically connected to the eighth power conductor. The seventh snap connector may be configured for connection to the fifth snap connector, thereby electrically coupling the fifth power conductor to the eighth power conductor. The eighth snap connector may be configured for connection to the sixth snap connector, thereby electrically coupling the sixth power conductor to the eighth power conductor. When (i) the first snap connector is connected to the third snap connector, (ii) the second snap connector is connected to the fourth snap connector, (iii) the fifth snap connector is connected to the seventh snap connector, (iv) the sixth snap connector is connected to the eighth snap connector, (v) the first light panel is disposed adjacent to the third light panel, and (vi) the second light panel is disposed adjacent to the fourth light panel, over the first, second, third, and fourth substrates the first, second, third, and fourth light-emitting elements may be spaced apart at a constant pitch, and the pitch may be maintained among the first, second, third, and fourth substrates.

The first power conductor may be disposed proximate a first edge of the first substrate. The first edge may be folded to thereby increase an effective width of the first power conductor. The second power conductor may be disposed proximate a second edge of the first substrate, the second edge being opposite the first edge. The second edge may be folded to thereby increase an effective width of the second power conductor. A first frame element may be disposed proximate a first edge of the first substrate. A second frame element may be disposed proximate a second edge of the first substrate, the second edge being opposite the first edge. The first power conductor may be disposed proximate the first edge of the first substrate, and/or the second power conductor may be disposed proximate the second edge of the first substrate. The first frame element may include or consist essentially of a first electrically conductive element. The first frame element may be configured to electrically couple the first electrically conductive element to the first power conductor, thereby decreasing an effective electrical resistivity of the first power conductor. The second frame element may include or consist essentially of a second electrically conductive element. The second frame element may be configured to electrically couple the second electrically conductive element to the second power conductor, thereby decreasing an effective electrical resistivity of the second power conductor.

A first frame element may be disposed at least partially on the first substrate. The first frame element may be attached to the first substrate by glue, adhesive, tape, conductive tape, conductive adhesive, anisotropic conductive adhesive, a magnet, a mechanical fastener, and/or a rivet. The first frame element may define therein at least one through-hole for mounting the lighting system to a mounting surface. The first frame element may include or consist essentially of a first portion, a second portion, and at least one hinge section coupling the first and second portions. The first substrate may be disposed between the first portion and the second portion. The first frame element may include or consist essentially of a first electrically conductive element. The first power conductor may include or consist essentially of a plurality of electrically discontinuous sections. The first electrically conductive element may be configured to electrically connect at least two electrically discontinuous sections of the first power conductor. The first frame element may be flexible. The first frame element may be positionable, whereby the first frame element maintains a deformed configuration in the absence of a deforming force. The first frame element may include or consist essentially of at least one spacer. The at least one spacer may be fixed or adjustable. The at least one spacer is configured to space the first light panel apart from a mounting surface. The lighting system may include an optic. The at least one spacer may be configured to space the first light panel apart from the optic. The optic may include or consist essentially of a lens, a diffuser, a refractive optic, a reflective optic, a Fresnel optic, a fabric, a translucent material panel, a graphic panel, and/or a membrane. The at least one spacer may have a reflectance greater than 75%, or even greater than 85%, to a wavelength of light emitted by the first light-emitting elements.

The first light panel and/or the second light panel may have a substantially square shape. The first light panel and/or the second light panel may have a substantially rectangular shape. The first light panel and/or the second light panel may have a substantially hexagonal shape. The first light panel and/or the second light panel may have a substantially triangular shape. The first light panel and/or the second light panel may have a thickness in the range of 0.25 mm to 25 mm. The first light-emitting elements and/or the second light-emitting elements may emit substantially white light. The first light-emitting elements and/or the second light-emitting elements may include or consist essentially of light-emitting diodes. The first substrate and/or the second substrate may be flexible. The first and second substrates may include or consist essentially of polyethylene terephthalate. The first, second, third, and fourth power conductors may include or consist essentially of copper and/or aluminum. An optic may be disposed over the first light panel and/or over the second light panel. The optic may include or consist essentially of a lens, a diffuser, a refractive optic, a reflective optic, a Fresnel optic, a fabric, a translucent material panel, a graphic panel, and/or a membrane. A collective thickness of the first light panel and the optic may be less than 500 mm, or even less than 100 mm.

In another aspect, embodiments of the invention feature a lighting system that includes or consists essentially of a first light panel and a second light panel. The first light panel includes or consists essentially of a first substrate, first and second spaced-apart power conductors disposed on the first substrate, a plurality of first light-emitting elements disposed on the first substrate and electrically connected to the first and second power conductors, a first frame element (i) disposed at least partially on the first substrate and (ii) including or consisting essentially of a first electrically conductive element, the first electrically conductive element being electrically connected to the first power conductor, and a second frame element (i) disposed at least partially on the first substrate and (ii) including or consisting essentially of a second electrically conductive element, the second electrically conductive element being electrically connected to the second power conductor. The second light panel includes or consists essentially of a second substrate, third and fourth spaced-apart power conductors disposed on the second substrate, a plurality of second light-emitting elements disposed on the second substrate and electrically connected to the third and fourth power conductors, a third frame element (i) disposed at least partially on the second substrate and (ii) including or consisting essentially of a third electrically conductive element, the third electrically conductive element being electrically connected to the third power conductor, and a fourth frame element (i) disposed at least partially on the second substrate and (ii) including or consisting essentially of a fourth electrically conductive element, the fourth electrically conductive element being electrically connected to the fourth power conductor. The first frame element is configured for connection to the third frame element, thereby electrically coupling the first power conductor to the third power conductor. The second frame element is configured for connection to the fourth frame element, thereby electrically coupling the second power conductor to the fourth power conductor.

Embodiments of the invention may include one or more of the following in any of a variety of combinations. The first frame element may be configured for connection to the third frame element via a first snap connector. The second frame element may be configured for connection to the fourth frame element via a second snap connector. The first frame element may be configured for connection to the third frame element via a first magnet. The second frame element may be configured for connection to the fourth frame element via a second magnet. The first frame element may be configured for connection to the third frame element via a first wire. The second frame element may be configured for connection to the fourth frame element via a second wire. The first substrate may include a plurality of first conductive traces thereon. The plurality of first light-emitting elements may be spaced apart and interconnected, via the plurality of first conductive traces, into one or more first light-emitting strings. Each first light-emitting string may have (i) a first end electrically connected to the first power conductor and/or (ii) a second end electrically connected to the second power conductor. One or more first control elements may be configured to control current to one or more of the first light-emitting strings. The one or more first control elements may be disposed on the first substrate and/or the second substrate. The one or more first control elements may each be electrically coupled to at least one first light-emitting string. The first substrate may be separable, via a cut spanning the first and second power conductors and not crossing a first light-emitting string, into two partial substrates each including or consisting essentially of (i) one or more first light-emitting strings, and (ii) portions of the first and second power conductors configured to supply power to and thereby illuminate the one or more first light-emitting strings of the partial substrate.

Along each first light-emitting string, a first pitch at which the first light-emitting elements are spaced may be substantially constant. The one or more first light-emitting strings may include or consist essentially of a plurality of first light-emitting strings. Over the first substrate, the first light-emitting elements may be spaced apart at the first pitch, and the first pitch may be maintained between first light-emitting elements of different ones of the first light-emitting strings. When the first frame element is connected to the third frame element and the second frame element is connected to the fourth frame element, over the first and second substrates, the first and second light-emitting elements may be spaced apart at the first pitch, and the first pitch may be maintained between the first and second substrates. The lighting system may include a third light panel and a fourth light panel. The third light panel may include or consist essentially of a third substrate, fifth and sixth spaced-apart power conductors disposed on the third substrate, a plurality of third light-emitting elements disposed on the third substrate and electrically connected to the fifth and sixth power conductors, a fifth frame element (i) disposed at least partially on the third substrate and (ii) including or consisting essentially of a fifth electrically conductive element, the fifth electrically conductive element being electrically connected to the fifth power conductor, and a sixth frame element (i) disposed at least partially on the third substrate and (ii) including or consisting essentially of a sixth electrically conductive element, the sixth electrically conductive element being electrically connected to the sixth power conductor. The fourth light panel may include or consist essentially of a fourth substrate, seventh and eighth spaced-apart power conductors disposed on the fourth substrate, a plurality of fourth light-emitting elements disposed on the fourth substrate and electrically connected to the seventh and eighth power conductors, a seventh frame element (i) disposed at least partially on the fourth substrate and (ii) including or consisting essentially of a seventh electrically conductive element, the seventh electrically conductive element being electrically connected to the seventh power conductor, and an eighth frame element (i) disposed at least partially on the fourth substrate and (ii) including or consisting essentially of an eighth electrically conductive element, the eighth electrically conductive element being electrically connected to the eighth power conductor. The seventh frame element may be configured for connection to the fifth frame element, thereby electrically coupling the fifth power conductor to the eighth power conductor. The eighth frame element may be configured for connection to the sixth frame element, thereby electrically coupling the sixth power conductor to the eighth power conductor. When (i) the first frame element is connected to the third frame element, (ii) the second frame element is connected to the fourth frame element, (iii) the fifth frame element is connected to the seventh frame element, (iv) the sixth frame element is connected to the eighth frame element, (v) the first light panel is disposed adjacent to the third light panel, and (vi) the second light panel is disposed adjacent to the fourth light panel, over the first, second, third, and fourth substrates the first, second, third, and fourth light-emitting elements may be spaced apart at a constant pitch, and the pitch may be maintained among the first, second, third, and fourth substrates.

The first power conductor may be disposed proximate a first edge of the first substrate. The first edge may be folded to thereby increase an effective width of the first power conductor. The second power conductor may be disposed proximate a second edge of the first substrate, the second edge being opposite the first edge. The second edge may be folded to thereby increase an effective width of the second power conductor. The first frame element may be disposed proximate a first edge of the first substrate, and/or the second frame element may be disposed proximate a second edge of the first substrate, the second edge being opposite the first edge. The first power conductor may be disposed proximate the first edge of the first substrate, and/or the second power conductor may be disposed proximate the second edge of the first substrate. The first frame element may be attached to the first substrate by glue, adhesive, tape, conductive tape, conductive adhesive, anisotropic conductive adhesive, a magnet, a mechanical fastener, and/or a rivet. The first frame element may define therein at least one through-hole configured for mounting the lighting system to a mounting surface. The first frame element may include or consist essentially of a first portion, a second portion, and at least one hinge section coupling the first and second portions. The first substrate may be disposed between the first portion and the second portion. The first power conductor may include or consist essentially of a plurality of electrically discontinuous sections, and the first electrically conductive element may be configured to electrically connect at least two electrically discontinuous sections of the first power conductor.

The first frame element and/or the second frame element may be flexible. The first frame element and/or the second frame element may be positionable (i.e., maintaining a deformed configuration in the absence of a deforming force). The first frame element may include or consist essentially of at least one spacer. The at least one spacer may be fixed or adjustable. The at least one spacer may be configured to space the first light panel apart from a mounting surface. The lighting system may include an optic. The at least one spacer may be configured to space the first light panel apart from the optic. The optic may include or consist essentially of a lens, a diffuser, a refractive optic, a reflective optic, a Fresnel optic, a fabric, a translucent material panel, a graphic panel, and/or a membrane. The at least one spacer may have a reflectance greater than 75%, or even greater than 85%, to a wavelength of light emitted by the first light-emitting elements. The first light panel and/or the second light panel may have a substantially square shape. The first light panel and/or the second light panel may have a substantially rectangular shape. The first light panel and/or the second light panel may have a substantially hexagonal shape. The first light panel and/or the second light panel may have a substantially triangular shape. The first light panel and/or the second light panel may have a thickness in the range of 0.25 mm to 25 mm. The first light-emitting elements and/or the second light-emitting elements may emit substantially white light. The first light-emitting elements and/or the second light-emitting elements may include or consist essentially of light-emitting diodes. The first substrate and/or the second substrate may be flexible. The first and second substrates may include or consist essentially of polyethylene terephthalate. The first, second, third, and fourth power conductors may include or consist essentially of copper and/or aluminum. An optic may be disposed over the first light panel and/or the second light panel. The optic may include or consist essentially of a lens, a diffuser, a refractive optic, a reflective optic, a Fresnel optic, a fabric, a translucent material panel, a graphic panel, and/or a membrane. A collective thickness of the first light panel and the optic may be less than 500 mm, or even less than 100 mm.

These and other objects, along with advantages and features of the invention, will become more apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations. Reference throughout this specification to “one example,” “an example,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present technology. Thus, the occurrences of the phrases “in one example,” “in an example,” “one embodiment,” or “an embodiment” in various places throughout this specification are not necessarily all referring to the same example. Furthermore, the particular features, structures, routines, steps, or characteristics may be combined in any suitable manner in one or more examples of the technology. As used herein, the terms “about,” “approximately,” and “substantially” mean±10%, and in some embodiments, ±5%. The term “consists essentially of” means excluding other materials that contribute to function, unless otherwise defined herein. Nonetheless, such other materials may be present, collectively or individually, in trace amounts.

Herein, two components such as light-emitting elements and/or optical elements being “aligned” or “associated” with each other may refer to such components being mechanically and/or optically aligned. By “mechanically aligned” is meant coaxial or situated along a parallel axis. By “optically aligned” is meant that at least some light (or other electromagnetic signal) emitted by or passing through one component passes through and/or is emitted by the other. As used herein, the terms “phosphor,” “wavelength-conversion material,” and “light-conversion material” refer to any material that shifts the wavelength of light striking it and/or that is luminescent, fluorescent, and/or phosphorescent.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:

FIGS. 1A-1E are schematics of lighting panels in accordance with various embodiments of the invention;

FIG. 2A is a partial circuit diagram of a light sheet in accordance with various embodiments of the invention;

FIGS. 2B and 2C are partial schematics of light sheets in accordance with various embodiments of the invention;

FIGS. 2D and 2E are partial circuit topologies of light sheets in accordance with various embodiments of the invention;

FIG. 3 is a schematic of portions of a frame element in accordance with various embodiments of the invention;

FIGS. 4A-4E, 5A, and 5B are schematics of portions of a frame element in accordance with various embodiments of the invention;

FIGS. 5C and 5D are schematics of a frame element in accordance with various embodiments of the invention;

FIGS. 6 and 7A-7C are schematics of illumination systems in accordance with various embodiments of the invention;

FIGS. 7D-7F are schematics of tiled lighting panels in accordance with various embodiments of the invention;

FIG. 8A is a perspective view of a frame element incorporating an insulation-displacement connector in accordance with various embodiments of the invention;

FIG. 8B is a cross-sectional view of a portion of the frame element of FIG. 8A;

FIG. 8C is a schematic illustration of a lighting system incorporating four light panels in accordance with various embodiments of the invention;

FIGS. 9A and 9B are cross-sectional schematics of conductive elements incorporated into frame elements in accordance with various embodiments of the invention;

FIG. 10A is a plan-view schematic of joined light panels in accordance with various embodiments of the invention;

FIG. 10B is a cross-sectional schematic of joined frame elements in accordance with various embodiments of the invention;

FIG. 11A is a partial circuit diagram of a portion of a system in accordance with various embodiments of the invention;

FIG. 11B is a plan-view schematic of a portion of a light sheet in accordance with various embodiments of the invention;

FIG. 11C is a cross-sectional schematic of the light-sheet portion of FIG. 11B;

FIG. 11D is a cross-sectional schematic of the interior of a frame element in accordance with various embodiments of the invention;

FIGS. 12A-12D are cross-sectional schematics of frame elements in accordance with various embodiments of the invention;

FIG. 13A is a schematic diagram of an illumination system featuring two electrically connected light sheets in accordance with various embodiments of the invention;

FIG. 13B is a schematic cross-section of a clamping mechanism in accordance with various embodiments of the invention;

FIG. 14 is a schematic diagram of a lighting system in accordance with various embodiments of the invention;

FIGS. 15A-15E are schematic diagrams of light panels in accordance with various embodiments of the invention;

FIG. 16 is a cross-sectional schematic of a portion of a light panel in accordance with various embodiments of the invention;

FIGS. 17A-17C are schematic plan views of lighting systems in accordance with various embodiments of the invention;

FIGS. 18A-18D are cross-sectional schematics of light panels or light sheets incorporating electrical connectors in accordance with various embodiments of the invention;

FIGS. 18E and 18F are cross-sectional schematics of light panels or light sheets joined via electrical connectors in accordance with various embodiments of the invention;

FIGS. 18G and 18H are views of electrical connectors in accordance with various embodiments of the invention;

FIG. 19A is a perspective view of a light panel or light sheet incorporating tabs and electrical connectors in accordance with various embodiments of the invention;

FIGS. 19B-19D are magnified views of portions of light panels or light sheets that are folded and feature electrical connectors in accordance with various embodiments of the invention;

FIG. 19E is a perspective view of a light panel or light sheet having folded peripheral portions in accordance with various embodiments of the invention;

FIG. 19F is a schematic comparison of power conductor width of folded and unfolded light sheets or light panels in accordance with various embodiments of the invention;

FIG. 19G is a schematic of a portion of a light sheet or light panel incorporating multiple folds in accordance with various embodiments of the invention;

FIG. 19H is a perspective view of a light panel or light sheet having folded peripheral portions in accordance with various embodiments of the invention;

FIG. 19I is a schematic of a portion of a light sheet or light panel incorporating multiple folds in accordance with various embodiments of the invention;

FIGS. 19J, 19K, and 19L are schematics of power conductor configurations in accordance with various embodiments of the invention;

FIGS. 20A and 20B are schematic plan views of light panels or light sheets in accordance with various embodiments of the invention;

FIGS. 20C and 21A-21E are schematic plan views of lighting systems incorporating electrically connected light panels or light sheets in accordance with various embodiments of the invention; and

FIG. 21F is a schematic side view of an installed lighting system in accordance with various embodiments of the invention.

DETAILED DESCRIPTION

FIG. 1A depicts an exemplary lighting panel 100 in accordance with embodiments of the present invention, although alternative systems with similar functionality are also within the scope of the invention. In various embodiments, lighting panel 100 includes or consists essentially of one or more flexible light sheets 110 and optionally one or more flexible, positionable, semi-rigid, substantially rigid, or rigid frame elements 120. (FIG. 1A depicts two such frame elements, frame elements 120, 120′.) Frame elements 120, 120′ may be disposed on all or portions of one or more edges of light sheet 110. While FIG. 1A shows lighting panel 100 having two frame elements 120, 120′ on opposite sides of light sheet 110, this is not a limitation of the present invention, and in other embodiments lighting panel 100 may have frame elements 120 on one side of light sheet 110, three sides of light sheet 110, or four sides of light sheet 110 (i.e., one or more sides, or even all sides, of a polygonal light sheet 110). In various embodiments of the present invention lighting panel 100 may not include any frame elements. In various embodiments, one or more frame elements 120 may be disposed on a non-edge region of light sheet 110, e.g., a center portion within the edges defining light sheet 110, while in other embodiments one or more portions of a frame element 120 may be disposed such that a portion of the frame element 120 extends beyond one or more edges of light sheet 110.

While FIG. 1A shows frame elements 120 having a length about the same as the length of the side of light sheet 110 on which they are formed, this is not a limitation of the present invention, and in other embodiments frame elements 120 may be longer or shorter than the associated dimension of light sheet 110. FIG. 1B shows an example of frame element 120 having a length shorter than the associated dimension of light sheet 110; however, in other embodiments frame element 120 may have a length longer than the associated dimension of light sheet 110. While FIGS. 1A and 1B show light sheet 110 as substantially square, this is not a limitation of the present invention, and in other embodiments light sheet 110 may be rectangular, triangular, wedge or pie-section shaped, rhombohedral, hexagonal, circular, ellipsoidal, or have any arbitrary shape. FIGS. 1C, 1D, and 1E show examples of rectangular, triangular, and circular light sheets 110 respectively.

In various embodiments, light sheet 110 includes or consists essentially of an array of light-emitting elements (LEEs) electrically coupled by conductive traces formed on a flexible substrate, for example as described in U.S. patent application Ser. No. 13/799,807, filed Mar. 13, 2013 (the '807 application), or U.S. patent application Ser. No. 13/970,027, filed Aug. 19, 2013 (the '027 application), the entire disclosure of each of which is herein hereby incorporated by reference.

In various embodiments, various elements such as frame elements, substrates, or light sheets are “flexible” in the sense of being pliant in response to a force and resilient, i.e., tending to elastically resume an original or substantially original configuration upon removal of the force. Such elements may have a radius of curvature of about 50 cm or less, or about 20 cm or less, or about 5 cm or less, or about 1 cm or less, or even about 0.5 cm or less. In various embodiments, flexible elements may have a Young's Modulus less than about 50×10⁹ N/m², less than about 10×10⁹ N/m², or even less than about 5×10⁹ N/m². In various embodiments, flexible elements may have a Shore A hardness value less than about 100; a Shore D hardness less than about 100; and/or a Rockwell hardness less than about 150. In various embodiments, such elements may permit folding and or creasing, for example folding of the element over on itself (e.g., folding a portion of the element through substantially 180°, such that the folded portion lays on and is substantially parallel to the non-folded portion) without substantially impairing the functionality of conductive traces on the substrate and/or the functionality of the substrate. For example, in various embodiments, the functionality of the conductive trace may include a resistance or conductance value, a reliability metric, a mechanical metric, or the like. In various embodiments, the functionality of the substrate may include a resistance value, a reliability metric, a mechanical metric, or the like. In various embodiments, a folded or creased element may have a radius of curvature of less than 2 mm, or less than 1 mm or less than 0.05 mm. In various embodiments of the present invention, the elements may be folded or creased without damage or substantial damage to the elements, for example to the substrate and/or conductive trace. In various embodiments of the present invention, the elements may be folded or creased without changing or substantially changing the electrical and/or mechanical and/or thermal and/or optical properties of the elements.

In various embodiments, various elements such as substrates, light sheets, or frame elements may be positionable, in the sense that they are pliant in response to a force, as with a flexible element, but upon removal of the force, retain or substantially retain the deformed shape. In various embodiments such positionable characteristics may be achieved by plastic deformation of the element; however, this is not a limitation of the present invention, and in other embodiments the positionable characteristic may be achieved without substantial plastic deformation of the element. Such elements may have essentially any radius of curvature, but in particular may have a radius of curvature of about 50 cm or less, or about 20 cm or less, or about 5 cm or less, or about 1 cm or less, or even about 0.5 cm or less.

In various embodiments, elements such as frame elements may be rigid or substantially rigid, in the sense that they are not pliant in response to a force, i.e., tending to break or crack in response to a force. In various embodiments, various elements such as substrates, light sheets, or frame elements are semi-rigid, i.e., having a deformation characteristic between that of a flexible element and a rigid or substantially rigid element. Such elements may have a radius of curvature greater than about 50 cm.

FIG. 2A depicts an exemplary circuit topology, in accordance with embodiments of the present invention, which features conductive traces 260, at least two power conductors 210, 220, multiple LEEs 230, and optional control elements (CEs) 240. In various embodiments, LEEs 230 may be configured in a regular periodic array, for example a substantially square or rectangular array, where LEEs 230 are separated by pitch (or “spacing”) 223 in the one direction (for example vertical direction) by pitch 225 in a substantially orthogonal direction (for example the horizontal direction; see FIG. 2C). In various embodiments, pitch 225 is the same as or substantially the same as pitch 223.

FIG. 2A shows two power conductors 210, 220, which may be used to provide power to strings 250 of LEEs 230. Each string 250 may include two or more electrically coupled LEEs 230. LEEs 230 in string 250 may be electrically coupled in series, as shown in FIG. 2A; however, this is not a limitation of the present invention, and in other embodiments other examples of electrical coupling may be utilized, for example LEEs in parallel or in any combination of series and parallel connections. FIG. 2A shows CE 240 in series with string 250; however, this is not a limitation of the present invention, and in other embodiments CE 240 may have different electrical coupling between power conductors 210, 220, or may be absent altogether. For example, in various embodiments CE 240 may be separately electrically coupled to power conductors 210, 220 and to the LEE string 250, while in other embodiments each CE 240 may be electrically coupled to two or more strings. The number of strings electrically coupled to each CE 240 is not a limitation of the present invention. Combinations of structures described herein, as well as other electrical connections, all fall within the scope of the present invention. Power conductors 210, 220 may be used to provide power to strings 250, for example AC power, DC power, or power modulated by any other means. Each control element 240 may be, for example electrically connected to at least one light-emitting string 250 and configured to utilize power supplied from the power conductors 210, 220 to control power (e.g., supply a substantially constant current) to the light-emitting string(s) 250 to which it is electrically connected.

Referring to FIGS. 2B and 2C that depict schematics of exemplary light sheets 110, light sheet 110 features an array of LEEs 230 each electrically coupled between conductive traces 260, and power conductors 210 and 220 providing power to conductive traces 260 and CEs 240, all of which are disposed over a substrate 265. As utilized herein, a “wiring board” refers to a substrate for LEEs with or without additional elements such as conductive traces or CEs. A wiring board may also be referred to as a light sheet or a circuit board. FIG. 2B shows an enlarged portion of an exemplary light sheet 110. In the exemplary embodiment depicted in FIG. 2B, power conductors 210, 220 are spaced apart from each other and light-emitting strings (or simply “strings”) 250 are connected in parallel across power conductors 210, 220. In various embodiments, for example as shown in FIG. 2B, strings 250 do not cross (i.e., intersect) each other. In other words, power conductors 210, 220 are oriented in one direction and strings 250 are oriented such that they span power conductors 210, 220 in a different direction. As shown in FIG. 2B, strings 250 may be substantially perpendicular to power conductors 210, 220. However, this is not a limitation of the present invention, and in other embodiments at least some segments (i.e., portions connecting two or more LEEs 230), or even the entire strings 250, may define a line (not necessarily a straight line) that is not perpendicular to power conductors 210, 220 yet is (at least for an entire string 250) not parallel to power conductors 210, 220. In other embodiments strings 250 may intersect, for example one string 250 splitting into two or more strings 250, or two or more strings 250 joining to form a reduced number of strings 250. In various embodiments, conductive traces 260 may cross over each other without being electrically coupled to each other, and in various embodiments, strings 250 may cross over or under each other without being electrically coupled to each other. In various embodiments, all or a portion of one or more strings 250 may extend beyond the area disposed between the power conductors 210, 220. Various examples of string geometries and conformations utilized in embodiments of the present invention are detailed in the '807 and '027 applications.

As shown in FIGS. 2B and 2C, LEEs 230 may be positioned across substrate 265 in a regular periodic array, although this is not a limitation of the present invention, and in other embodiments LEEs 230 may occupy any positions on light sheet 110. Power conductors 210 and 220 provide power to each LEE string, for example the string 250 encircled by the dashed line in FIG. 2B. Each LEE string 250 typically includes multiple conductive traces 260 that interconnect multiple LEEs 230, as well as one or more CEs 240, which in FIG. 2B is in series with LEEs 230. String 250 shown in FIG. 2B is a folded string, i.e., a string that has three segments electrically coupled in series but positioned as three adjacent segments. A string segment is a portion of a string spanning all or a portion of the region between power conductors (e.g., power conductors 210 and 220 in FIG. 2B). In light sheet 110, some string segments may include LEEs 230 and others may not. However, in other embodiments, the distribution and position of LEEs 230 along conductive elements 260 and string segments may be different. In various embodiments, a string 250 may be a straight string, i.e., a string with no folds, as shown in FIG. 2C. (The example shown in FIG. 2C does not include CEs 240.) In a straight string, one end of string 250 is electrically coupled to power conductor 210, while the other end of string 250 is electrically coupled to power conductor 220 with no turns or corners therebetween. As will be discussed, the number of segments in a string 250 is not a limitation of the present invention. Various examples of straight and folded strings utilized in embodiments of the present invention are detailed in the '807 and '027 applications.

FIGS. 2A and 2B illustrate three aspects of various embodiments in accordance with embodiments of the present invention. The first is the multiple strings 250 that are powered by the set of power conductors 210, 220. The second is the positional relationship between the locations of LEEs 230 and CE 240, which is disposed between the conductive traces 260 and between power conductors 210,220. The third is the inclusion of a CE 240 in each string of series-connected LEEs 230. Combinations of these three aspects enable light sheet 110 to be economically manufactured in very long lengths, for example in a roll-to-roll process, and cut to specified lengths, forming light sheets, while maintaining the ability to tile, or place light sheets adjacent to each other (e.g., in the length direction), with no or substantially no change in pitch between LEEs 230 or in the optical characteristics across the joint between two adjacent light sheets, as discussed in more detail in the '807 and '027 applications.

In an exemplary embodiment, CE 240 is configured to regulate the current or maintain a constant or substantially constant current through LEEs 230 of string 250. For example, in various embodiments, a constant or substantially constant voltage may be applied to power conductors 210, 220, which may, under certain circumstances may have some variation, or the sum of the forward voltages of LEEs 230 in different strings may be somewhat different, for example as a result of LEE manufacturing tolerances, or the component and/or operational values of the element(s) within CE 240 may vary, for example as a result of manufacturing tolerances or changes in operating temperature, and CE 240 acts to maintain the current through LEEs 230 substantially constant in the face of these variations. In other words, in various embodiments the input to the light sheet is a constant voltage that is applied to power conductors 210, 220, and CEs 240 convert the constant voltage to a constant or substantially constant current through LEEs 230. As will be described herein, the design of CE 240 may be varied to provide different levels of control or variation of the current through LEEs 230. In various embodiments, CEs 240 may control the current through LEEs 230 to be substantially constant with a variation of less than about ±25%. In various embodiments, CEs 240 may control the current through LEEs 230 to be substantially constant with a variation of less than about ±15%. In various embodiments, CEs 240 may control the current through LEEs 230 to be substantially constant with a variation of less than about ±10%. In various embodiments, CEs 240 may control the current through LEEs 230 to be substantially constant with a variation of less than about ±5%.

In various embodiments, as described herein, CEs 240 may, in response to a control signal, act to maintain a constant or substantially constant current through LEEs 230 until instructed to change to a different constant or substantially constant current, for example by an external control signal. In various embodiments, as described herein, all CEs 240 on a sheet may act in concert, that is maintain or change the current through all associated LEEs 230; however, this is not a limitation of the present invention, and in other embodiments one or more CEs 240 may be individually controlled and/or energized.

While FIG. 2A shows one exemplary circuit topology, this is not a limitation of the present invention, and in other embodiments other circuit topologies may be utilized. For example, in various embodiments the circuit may not include any CEs 240. In various embodiments of the present invention, the electrical topology may include one or more cross-connecting elements, for example which may electrically couple conductive elements in separate strings, for example as described in U.S. patent application Ser. No. 13/378,880, filed on Dec. 16, 2011, and U.S. patent application Ser. No. 13/183,684, filed on Jul. 15, 2011, the entirety of each of which is incorporated by reference herein. FIGS. 2D and 2E show two examples of such a cross-connection topology. In the circuit shown in FIG. 2D, each LEE 230 is cross-connected with adjacent LEEs 230, while in FIG. 2E, only some of LEEs 230 are cross-connected with adjacent LEEs 230.

In various embodiments of the present invention, frame elements 120 provide a rigid or semi-rigid support for light sheet 110. In various embodiments, a frame element 120 may include or consist essentially of a plastic material, for example acrylic, acrylonitrile butadiene styrene (ABS), polyethylene, thermoplastic polyurethane (TPU), or the like. In various embodiments, frame element 120 may include or consist essentially of one or more metals, such as aluminum, copper, or the like, or silicone, wood or other materials. In various embodiments, frame element 120 may include or consist essentially of a combination of materials.

In various embodiments of the present invention, frame elements 120 provide a flexible support for light sheet 110. In various embodiments of the present invention, frame elements 120 provide a positionable support for light sheet 110.

In various embodiments, light sheet 110 has one or more openings (or “holes”), for example along the edge of light sheet 110, that mate to frame element 120, and frame element 120 has one or more corresponding locating pins over which the holes are positioned, to provide accurate and repeatable positioning of light sheet 110 in frame element 120. FIG. 3 shows a schematic of one embodiment that features locating pins 310 on frame element 120 and locating holes 320 in light sheet 110. FIG. 3 shows two light sheets, 110 and 110′. Light sheet 110 is positioned above frame element 120 while light sheet 110′ is positioned on frame element 120 such that locator pin 310 is at least partially inserted into locating hole 320. FIG. 3 shows one additional aspect of various embodiments of the present invention, in which a frame element 120 may be used to couple two or more light sheets 110 together into a single lighting system. While the structures shown in FIGS. 3 and 4A-4C use pins and holes to align one or more light sheets 110 to one or more frame elements 120, this is not a limitation of the present invention, and in other embodiments other techniques and/or structures may be utilized to align and/or hold light sheet 110 in frame element 120. For example, light sheet 110 may be aligned to frame element 120 using alignment marks on light sheet 110 and/or frame element 120. In various embodiments, light sheet 110 may be attached or fastened to frame element 120 by other means, for example screws, nuts and bolts, tape, adhesive, glue, external clamps, magnets, heat stakes, or the like. For example, FIG. 4D shows a two-piece frame element 120 fastened to light sheet 110 using a clamp or spring clamp 450. FIG. 4E shows another example in which frame element 120 (having a hinge 430) is fastened to light sheet 110 using an adhesive 460. In various embodiments, adhesive 460 may include or consist essentially of glue, tape, double-sided tape, or the like. The method of attaching light sheet 110 to frame element 120 is not a limitation of the present invention.

In various embodiments, frame element 120 has one or more hinges, such that the frame element 120 may be folded over and clamped to light sheet 110. In various embodiments, the locating pins in frame element 120 may act as a fastener that keeps (or helps keep) frame element 120 closed around light sheet 110. FIGS. 4A and 4B show a schematic of one embodiment of the present invention. FIG. 4A shows an unfolded frame element 120 that includes or consists essentially of a hinge 430, a locating pin 410 (that is composed of two or more protrusions), and a locating hole 420. In the depicted embodiment, locating pin 410 is designed to be compressed before being inserted through locating hole 420 and then to spring open to lock frame element 120 in the folded or closed position, as shown in FIG. 4B. In various embodiments, locating pin 410 may include or consist essentially of a snap hook instead of a compression element, as shown in FIGS. 5A (unfolded, or “open,” conformation) and 5B (folded, or “closed,” conformation). FIG. 4B shows light sheet 110 clamped into a folded frame element 120, where locating pin 410 has been inserted through locating hole 320 in light sheet 110 and through locating hole 420 in frame element 120. In various embodiments, frame element 120 and/or light sheet 110 may include holes that may be used for mounting frame element 120. FIG. 4C shows one example of such an embodiment, in which the light panel 100 has mounting hole 440 that goes through light sheet 110 and frame element 120. As described herein, mounting hole 440 includes or consists essentially of mounting hole 441 in frame element 120 and mounting hole 442 in light sheet 110. FIGS. 5C and 5D show schematic views of one embodiment of frame element 120 in the open and closed positions, respectively.

As described herein, light panel 100 may be designed to be cut to length, for example between strings 250, such that at least one and optionally both sections are operable after separation. In various embodiments, light panel 100 includes locating pins 310 and/or locating pins and holes 410, 420 and/or mounting holes 441, 442, to permit locating, clamping, and/or mounting of light panel 100 after light panel 100 (including or consisting substantially of one or more light sheets 110 and one or more frame elements 120) has been cut or separated into one or more portions. FIG. 6 shows a schematic of one embodiment showing two strings 250 and 250′ and a separation or cut region 620 on frame element 120 and a separation or cut region 610 on light sheet 110. As shown, the section including string 250 also includes mounting hole 440 and locating pin/fastener 410, and the section including string 250′ also includes mounting hole 440′ and locating pin/fastener 410′. If lighting panel 100 is separated along cur regions 620 and 610, each section has its own mounting hole and locating pin/fastener. In various embodiments, frame element 120 and light sheet 110 are designed to facilitate separation of lighting panel 100, for example by incorporating identified separation lines or regions on frame element 120 and/or light sheet 110. For example, in various embodiments separation line 610 may be formed on light sheet 110 by printing, or by a pattern in one or more conductive elements 260 and/or one or both power conductors 210, 220. In various embodiments, cut region 610 may be free of or substantially free of conductive elements 265. In various embodiments, light sheet 110 may include a coating over all or portions of substrate 265, power conductors 210, 220 and conductive elements 265 and separation line 610 may be formed in the coating material, or by the absence of the coating material in separation region 610. In various embodiments, separation line 620 on frame element 120 may include or consist essentially of markings on frame element 120, for example that are formed in frame element 120 or printed on frame element 120. In various embodiments, separation line 620 may include or consist essentially of a region engineered to separate more easily than adjacent regions of frame element 120, for example by having a reduced thickness compared to adjacent regions of frame 120 and/or perforations defined therein. In various embodiments, light panel 100 may be separated by cutting through frame element 120 in region 620 and light sheet 110 in region 610, for example with a scissors or knife or other cutting implement. The means of separation of light panel 100 is not a limitation of the present invention.

In various embodiments, light panel 100 may be mounted (e.g., to a mounting surface such as a wall, a ceiling, or a fixture), for example using screws or nails or other fasteners that may be inserted through mounting holes 440; however, this is not a limitation of the present invention, and in other embodiments light panel 100 may be mounted by other means, for example staples, tape, double-sided tape, magnets, a hook-and-loop fastener such as Velcro, or the like. In various embodiments, frame element 120 may include or incorporate mounting elements, for example double-sided tape or barbed pins that may be used to mount light panel 100 to a mounting surface.

In various embodiments, frame element 120 may be designed to have a width less than one-half of the pitch between LEEs 230 in the direction between frame elements 120 of adjacent light panels 100, such that if two light panels 100 are positioned next to each other, the pitch between nearest neighbor LEEs 230 on adjacent light panels 100 may be the same or substantially the same as the pitch between nearest neighbor LEEs 230 on each light panel 100. FIG. 7A shows a schematic of one example of this embodiment, depicting two light panels 100 and 100′, each featuring frame elements 120 and light sheets 110. As shown, a pitch 223 between LEEs 230 in the direction between frame elements is the same on light panels 100 and 100′ as it is between LEEs 230 on adjacent light sheets 110 and separated by frame elements 120. For example, in various embodiments LEE pitch 223 may be about 30 mm and frame element 120 may have a width in the range of about 5 mm to about 14 mm. In various embodiments, the width 710 of frame element 120 may be less than about 0.95×(pitch 223/2). In various embodiments, LEE pitch 223 may be about 20 mm and frame width 710 may be in the range of about 3 mm to about 9 mm.

FIG. 7B shows an example featuring four light panels 100 (one panel is encircled in a heavy dashed line), each panel 100 including two frame elements 120 on opposite sides of light sheet 110. As shown, pitch 223 is the same on one sheet as it is across frame elements 120 on adjacent sheets. In this example LEE pitch 223 is about 30 mm and frame width 710 is about 10 mm.

FIG. 7B shows an additional feature that may be incorporated in various embodiments of the present invention, identified as connector 720. Connector 720 may be utilized to join together two frame elements 120. In various embodiments, connector 720 may be designed such that pitch 225 is the same between nearest-neighbor LEEs 230 on adjacent light sheets 110 as it is on a single light sheet 110. In various embodiments, connector 720 may include or consist essentially of a portion of frame element 120 that extends beyond the length of light sheet 110 and includes a mechanism for attaching to an adjacent frame element 120. For example in various embodiments, as shown in FIG. 7C, connector 720′ may include a locating hole 730′ in frame element 120′ and that fits over a locating pin 740 on an adjacent frame element 120. In various embodiments, there may be a corresponding section 720 on the other end of frame element 120 (i.e., away from connector 720′, not shown in FIG. 7C). Locating hole 730′ and locating pin 740 are preferably positioned such that pitch 225 between LEEs in the direction along frame elements 120, 120′ is the same between light panels 100 as on an individual light panel 100, irrespective of the interface between the light panels 100. In various embodiments, locating pin 740 may also be used to position light sheet 110, similar to the approach discussed in reference to FIG. 3. In various embodiments, connector 720 may include a conventional electrical connector, such as a pin and jack system, where adjacent light sheets 120 are electrically coupled through the electrical connector. For example, a frame element may feature a connector electrically coupled to a power conductor on the light sheet, and the connector may be electrically coupled to a corresponding connector on an adjacent frame element. In various embodiments, the electrical connectors (or electrical portions of the connector) may mate directly, while in other embodiments a jumper wire may be used to electrically couple the two connectors. In various embodiments, such a system may be employed to electrically couple two or more light panels that are spaced apart from each other.

In various embodiments, the system shown in FIG. 7B includes frame elements 120 that, when attached to light sheet 110, have a width 710 of about 10 mm. In this example light sheet 110 has a square shape with a side length of about 300 mm. LEEs 230 have a pitch 223 of about 33 mm and a pitch 225 of about 30 mm. In this example connector 720 has a length beyond light sheet 110 in the range of about 5 mm to about 30 mm. These dimensions are exemplary and not limitations of the present invention.

The ability to tile light panels 100 in multiple directions provides a system that may be utilized to make arbitrarily large assemblies having uniform illuminance with no relatively darker areas in the joint regions between adjacent panels.

While the systems described in reference to FIGS. 6 and 7A-7C pertain to rectilinear light panels, this is not a limitation of the present invention, and in other embodiments other light panel shapes may be used. For example FIG. 7D shows a light panel system incorporating triangular light panels, FIG. 7E shows a system incorporating diamond-shaped light panels, and FIG. 7F shows a system incorporating hexagonal light panels. The shapes depicted in FIGS. 7D-7F are meant to be exemplary and are not limitations of the present invention.

In various embodiments, frame elements 120 provide support for light sheets 110 and a means for providing electrical connections to light sheet 110, for example to provide power to power conductors 210, 220. In various embodiments, frame elements 120 enable electrical coupling of one or more control signals, for example to dim or change the intensity of one or more LEEs 230 on light sheet 110, or to change the color of light emitted by LEEs 230, to light sheet 110.

FIG. 8A shows one embodiment of a frame element 120 that incorporates an insulation-displacement connector (IDC) 810 that is electrically coupled to one of power conductors 210, 220 on light sheet 110. (As utilized herein, an IDC is an electrical connector designed to be connected to the conductor(s) of an insulated wire or cable by a connection process that forces a selectively sharpened blade or blades (or other cutting or piercing element) through the insulation, bypassing the need to strip the wire of insulation before connecting.) Note that FIG. 8A shows two adjacent light panels. IDC 810 is formed or disposed into a hole in frame element 120, permitting access to it when light sheet 110 is attached to frame element 120. A wire 830, preferably an insulated wire, is inserted in IDC 810, which then provides electrical connection to power conductors 210, 220 on light sheet 110. FIG. 8B shows a cross-sectional schematic of such a structure, including a bottom portion 120B of the frame element, a top portion 120T of the frame element, and a hole 820 through which IDC 810 is inserted. IDC 810 is electrically coupled to power conductor 210, for example using solder, conductive adhesive, anisotropic conductive adhesive, or the like. Power conductor 210 is disposed on substrate 265. Referring back to FIG. 8A, after frame 120 is attached to light sheet 110, wire 830 is inserted into IDC 810 to electrically couple wire 830 to the underlying conductive element (not shown in FIG. 8A, and in FIG. 8B is exemplified by power conductor 210). Optional cap 840 may be used to aid in insertion of wire 830 into IDC 810 and/or to provide a protective cover over IDC 810. Optional guide elements 850 may be utilized to hold wire 830 into place on frame element 120. FIG. 8A also shows mounting holes 440. In the depicted embodiment, frame element 120 is installed substantially parallel to and over power conductors 210, 220 on light sheet 110.

FIG. 8C shows a schematic of a lighting system incorporating four light panels 100. The lighting system is powered by a driver 860, which is electrically coupled to light panels 100 through wires 830 and 830′. In various embodiments, this and similar arrangements permit the assembly of very large lighting systems without the need for the power conductors 210, 220 to have sufficient conductivity to support the entire assembly, because wires 830, 830′ have relatively larger conductivity and provide a low resistance shunt to power conductors 210, 220. In various embodiments, for example where it may be desirable to separate the light panel into smaller sections (e.g., in reference to FIG. 6), several IDCs 810 may be incorporated on light sheet 110 to permit separation into two or more portions, each of which has an IDC 810. In various embodiments, one or more electrical conductors may be incorporated into frame element 120. For example, in various embodiments, frame element 120 features a conductive element 910 that is attached to or embedded or partially embedded into frame element 120, as shown in FIG. 9A. Frame element 120 is clamped onto light sheet 110, forming an electrical and mechanical connection between conductive element 910 and power conductor 210. In various embodiments, conductive element 910 may be mounted on a surface of frame element 120, as shown in FIG. 9B. In various embodiments, conductive element 910 includes or consists essentially of one or more electrically conductive materials such as metals such as aluminum, copper, silver, gold, or the like. In various embodiments, conductive element 910 may include or consist essentially of a metal foil or metal strip. In various embodiments, conductive element 910 includes an electrically conductive tape, for example one that is conductive in both the lateral and z (i.e., through-thickness) directions, such that a low-resistance pathway forms between power conductor 210 and conductive element 910 and conductive element 910 forms a low-resistance pathway in parallel with power conductor 210. In various embodiments, conductive element 910 includes or consists essentially of a combination of materials, for example a metal layer over which is disposed a conductive adhesive or a conductive tape. In various embodiments, IDC 810 may be replaced by a pin or a barbed pin that mates with a corresponding connector or pierces a conductive element 910 mounted in frame element 120.

Electrical connection between adjacent light panels 100 and between light panels 100 and one or more power supplies or drivers may be formed through frame elements 120. In various embodiments, magnets of the appropriate polarity may be mounted or formed within or at the ends of frame elements 120, such that each frame may be mechanically and electrically connected through the magnets, for example as shown in FIG. 10A. In FIG. 10A, the opposing faces of magnets 1010 and 1020 have opposite polarities, so that the light panels may only be connected in one way. In various embodiments, this prevents incorrect connection of multiple light panels 100.

In various embodiments, frame element 120 may include one or more connectors or mechanisms for electrical coupling. In various embodiments, conductive elements such as conductive elements 910, as shown in FIGS. 9A and 9B, may be used to electrically couple two frames. FIG. 10B shows one example featuring the joining of frames 120 and 120′. In this example, the top portion 120T of frame element 120 and conductive element 910 extend beyond the end of substrate 265. In the second frame, the bottom portion 120B′ of frame element 120′ and conductive element 910′ extend beyond the edge of substrate 265′. Conductive elements 910 and 910′ are electrically coupled through a conductive element 1030, which may be, for example, a metallic conductor or a conductive adhesive, conductive glue, or conductive tape. FIG. 10B shows one embodiment of electrically coupling light panels 100; however, this specific method is not a limitation of the present invention, and in other embodiments other methods of electrically coupling light panels 100 may be employed.

In various embodiments, wires may be soldered or otherwise electrically coupled to power conductors 210, 220, and multiple light panels 100 may be electrically coupled through standard wiring techniques, for example using connectors, wire nuts, soldering, or the like. For example, in various embodiments connectors may be formed on frame elements 120 and electrically conductive jumpers may be used to electrically couple adjacent light panels 100. While much of the discussion herein has been related to lighting systems in which the light panels are butted up next to each other, this is not a limitation of the present invention, and in other embodiments one or more light panels in a system may be spaced apart from the others. In such embodiments, relatively longer jumpers may be used to connect the light panels together.

In various embodiments, a frame element 120 may include more than one conductive element 910. For example, conductive elements in frame element 120 may be used, in addition to powering light panel 100, to provide communication and control signals to and from light panel 100. In various embodiments, conductive elements in or on frame 120 may be used to provide electrical crossovers, i.e., to permit additional circuitry complexity while still using only one layer of conductive elements 260 on substrate 265. For example, FIG. 11A shows an electrical schematic of a system having two different LEEs 230, 230′. In various embodiments, LEE 230 may have a different color than LEE 230′, or a different intensity, or a different light distribution pattern, or a difference in any other electrical and/or optical property. In various embodiments, LEEs 230 and 230′ may both emit white light, but with different color temperatures, and the color temperature of the light panel may be adjusted by changing the light intensity emitted by strings with different color-temperature LEEs. For example in various embodiments LEEs 230 may have a correlated color temperature (CCT) of about 2000K and LEEs 230′ may have a CCT of about 10,000K, and the CCT of the ensemble may be varied between about 2000K and about 10,000K by varying the power delivered to strings having LEEs 230 and 230′. In various embodiments, LEEs 230 may have a CCT of about 2700K and LEEs 230′ may have a CCT of about 6000K, and the CCT of the ensemble may be varied between about 2700K and about 6000K by varying the power delivered to strings having LEEs 230 and 230′.

In various embodiments, the lighting system is driven by a substantially constant voltage supply that is pulse-width modulated, that is the voltage is kept substantially the same during the “on” phase and the light intensity is varied by changing the duty cycle, or the ratio of “on” to “off” time of the power signal. The circuit of FIG. 11A requires the power to the two different types of strings to be modulated separately, and thus requires three, or perhaps four (if separate returns are required) conductors. As shown in the schematic of FIG. 11A, this may require an electrical cross-over. While light sheets with multiple conductive layers may be manufactured, these are relatively more expensive. In various embodiments of the present invention, conductive elements within frame element 120 may form one or more electrical cross-overs, permitting circuits such as that shown in FIG. 11A to be realized with a light sheet with only one conductive layer.

FIG. 11B shows one example of a pattern of power conductor traces for power conductors 220 and 220′, that, combined with the frame element of FIG. 11C, permit realization of circuits requiring crossovers with a light sheet having a single conductive layer. FIG. 11B shows a portion of a light sheet, including substrate 265 on which power conductors 220 and 220′ as well as conductive elements 260 have been formed. Conductive elements 260 electrically couple LEEs 230, such that LEEs 230′ are electrically coupled to power conductor 220′ and LEEs 230 are electrically coupled to power conductor 220. However, as shown in FIG. 11B, power conductor 220 is discontinuous and requires a crossover in a region 1100 to form a complete circuit. FIG. 11C shows a cross-section of the structure of FIG. 11B through cut-line A-A′. As shown in FIG. 11C, conductive element 910 associated with power conductor 220 in top frame 120T is formed such that it does not electrically couple with power conductor 220′. In various embodiments, this may be achieved by spacing conductive element 910 apart from power conductor 220′, while in other embodiments an insulating layer, for example plastic or insulating tape or paper may be positioned between power conductor 220′ and conductive element 910. Not shown in FIG. 11C is conductive element 910′, which is associated with power conductor 220′, in top frame element 120T. FIG. 11D shows a plan view of the inside of top frame element 120T, showing both conductive elements 910 and 910′, where conductive element 910 has region 1100 that is designed to prevent electrical coupling to the underlying portion of power conductor 220′.

While FIGS. 11A-11D show a system having one level of cross-over, this is not a limitation of the present invention, and in other embodiments more than one level of cross-over may be utilized. In various embodiments, two levels may be utilized, with a light panel having two frame elements, with each frame element having one level of cross-over. In various embodiments, more than one level of cross-over may be utilized in a single frame element 120. It should be noted that the system shown in FIG. 11B has three LEEs 230 in each string; however, this is not a limitation of the present invention, and in other embodiments more LEEs may be utilized in each string. While FIG. 11C shows one form of cross-over, this is not a limitation of the present invention, and in other embodiments other types of cross-overs may be formed. For example, cross-overs may be formed using any of the approaches described herein for electrically coupling multiple frame elements together.

In various embodiments, additional elements may be added to frame element 120 to provide added functionality. For example, in various embodiments frame element 120 may include one or more spacers 1210 to space light panel 100 away from a mounting surface 1220, as shown in FIG. 12A. In various embodiments, frame element 120 may include spacers to aid in maintaining a specific gap between the light sheet and an overlying optic, diffuser or translucent panel, and/or graphic panel 1240. (Herein, a “graphic panel” is a panel overlying a lighting system that includes therein or thereon a pattern (e.g., words, images, graphics, etc.) for display when illuminated by the lighting system.) In various embodiments, such spacers may be fixed spacers 1230, as shown in FIG. 12B, or they may be adjustable spacers 1250, for example as shown in FIG. 12C where the spacers 1250 screw into the frame element 120, thereby controlling the offset distance. In various embodiments, diffuser 1240 may be positioned along the shaft of spacer 1250, for example by using clamps, a threaded shaft and bolts, or by other means. In various embodiments, frame element 120 may include a track or slot 1260 to hold one or more overlying panels or diffusers, as shown in FIG. 12D.

While FIGS. 12B-12D show one or more spacers 1230 attached to (or part of) frame element 120, this is not a limitation of the present invention, and in other embodiments one or more spacers 1230 may be disposed on light sheet 110, for example on light sheet 110 between LEEs 230. In various embodiments, spacers 1230 may be positioned, shaped, or constructed of one or more materials to minimize the impact of the spacer on the spatial and/or spectral light distribution. For example, in various embodiments of the present invention, a spacer or a portion of a spacer may include or consist essentially of a transparent material. In various embodiments, a spacer or a portion of a spacer may be reflective to a wavelength of light emitted by LEEs 230. For example, the spacer (or portion thereof) may have a reflectance greater than 75% to a wavelength of light emitted by LEEs 230. In various embodiments of the present invention, a spacer or a portion of the spacer may have specular reflectance or a diffuse reflectance. In various embodiments, a spacer or a portion of a spacer may have a white surface or be coated with a white material having a diffuse reflectance to a wavelength of light emitted by LEEs 230. In various embodiments, a portion of the conductive trace material may be removed from the substrate in one or more spacer regions, for example to aid in positioning of the spacer. In various embodiments, a portion of the substrate material may be removed in one or more spacer regions, for example to facilitate the mounting of the spacer to the underlying support structure.

In various embodiments, light sheets may be electrically connected together through an array of conductive elements mounted over the mounting surface. FIG. 13A shows an example of such a system that includes or consists of power elements 1310 and 1320 to which one or more light sheets 110 may be electrically coupled and mechanically attached. Power elements 1310 and 1320 may be metallic conductors, for example wires, bare wires, or bus bars, that are mounted on the mounting surface. In this approach, the layout of power elements 1310 and 1320 in part determines the position of light sheets 100, i.e., they determine the position in one direction, while the position in the orthogonal direction may be varied by moving the light sheet along the power elements. As shown in FIG. 13A, light sheets 110 may be spaced apart; however, this is not a limitation of the present invention, and in other embodiments they may be butted together to maintain LEE 230 pitch between adjacent light sheets 110. In various embodiments, light sheet 110 may be electrically and mechanically coupled to power elements 1310, 1320 by a clamp mechanism, for example a clamp 1340, as shown in FIG. 13B. Other methods for electrically coupling and mechanically attaching light sheet 110 to power elements 1310, 1320 include conductive tape, adhesive, screws, rivets, or the like. In various embodiments, a frame element may be combined with this approach to permit attachment and electrical coupling of the light panel to the power elements by an attachment in frame element 120. One aspect of this approach is that length adjustment of light sheet 110 may be accomplished by cutting the light sheet itself and mounting it to power elements that have been previously fabricated to the desired length. In various embodiments, the features described with respect to FIGS. 12A-12D may be incorporated into this embodiment featuring an array of power lines. In various embodiments, one or more signal or control lines may also be incorporated to provide a means for control and communication to one or more light panels or light sheets, or signals may be incorporated or modulated on the power supply lines.

FIG. 14 shows an example of a lighting system of the present invention, including power supply or driver 860 and four light panels 100. While four light panels are shown in FIG. 14, this is not a limitation of the present invention, and in other embodiments fewer or more light panels may be incorporated. In some embodiments, a system may include more than 20 light panels or more than 100 light panels. In various embodiments, wires 830 and 830′ may be connected to the same edge of light panel 100, as shown in FIG. 14, in contrast to the wiring schematic shown in FIG. 8C. In the system of FIG. 14, each light panel 100 includes power conductors 210, 220. Power conductors 210 are electrically coupled to wire 830, while power conductors 220 are electrically coupled to wire 830. In this way, the array of light panels 100 may be energized from only one side of the array. (Not shown in FIG. 14 for clarity, but discussed herein, are optional frame 120 and electrical connections between power conductors 210, 220 on adjacent sheets.)

In various embodiments, driver 860 is a substantially constant voltage supply, the output of which is pulse-width modulated to permit dimming of LEEs 230 on light panels 100. In various embodiments, the lighting system is a UL class 2 system having an operating voltage not exceeding 60 V.

In various embodiments, light panel 100 is square, having a side dimension in the range of about 10 cm to about 100 cm. In various embodiments, LEE pitches 223 and 225 are each in the range of about 5 mm to about 50 mm.

While frame elements 120 in FIGS. 5A-5D, 6, 7A, 7B, 8A, and 8C have been depicted as straight or substantially straight, this is not a limitation of the present invention, and in other embodiments frame elements may have more than one straight portions, as shown in FIG. 15A, or may be curved, as shown in FIG. 15B, or may include straight or curved elements, as shown in FIG. 15C. The shape or geometry of frame element 120 is not a limitation of the present invention. For example, the structure shown in FIG. 15B may be used to form a free-standing or partially free-standing light panel structure as shown in FIG. 15D, or may be mounted to a shaped surface having substantially the same shape as the shaped light panel, as shown in FIG. 15E. In various embodiments, structures such as those shown in FIGS. 15D and 15E may also be formed using flexible or semi-rigid light panels.

In various embodiments of the present invention, the light panel may be positionable. In such embodiments, the light panel may be flexible, but when deformed, it retains the deformed position, or substantially the deformed position, after the deforming force is removed. Such embodiments may also be used to form structures such as those shown in FIGS. 15A-15E. In various embodiments, a positionable frame element 110 may include or consist essentially of a flexible material combined with a deformable but relatively inflexible material, such as a wire. FIG. 16 depicts a cross-section of an exemplary positionable frame element including a flexible body 1610 surrounding a wire or positionable element 1620; however, this is not a limitation of the present invention, and in other embodiments other means may be utilized to construct a positionable frame element or a positionable light panel.

In various embodiments of the present invention, light panel 100 may be water-resistant or waterproof. In various embodiments, light panel 100 may meet IP65, IP66, IP67, or IP68 environmental ratings. (One method for rating different levels of environmental protection is an IP rating as specified by International Protection Marking in International Electrotechnical Commission (IEC) standard 60529, providing classification of degrees of protection provided by enclosures for electrical equipment, the entirety of which is hereby incorporated by reference herein. In general for an IP XY rating, “X” indicates the level of protection for access to electrical parts and ingress to solid foreign objects, while “Y” indicates the level of protection for ingress of harmful water. For example, an IP44 rating provides access and ingress protection for objects greater than about 1 mm and protection from water splashing on the system. In another example, an IP66 rating provides a dust-tight enclosure and protection from water jets incident on the system. Specific details of the requirements and test method are detailed within the IP specification.) In various embodiments, light sheet 110 may be encased or encapsulated in a waterproof or substantially waterproof coating, for example including or consisting essentially of silicone, polyurethane, or the like, as detailed in U.S. patent application Ser. No. 14/301,859, filed on Jun. 11, 2014, the entire disclosure of which is incorporated by reference herein. In various embodiments, the coating may be a conformal coating, for example having a thickness in the range of about 20 μm to about 1000 μm. In various embodiments, light sheet 110 may be potted, encased or encapsulated in a layer of waterproof or substantially waterproof material, for example silicone or polyurethane or the like.

In various embodiments of the present invention, a lighting system may include or consist essentially of multiple light panels 100, as shown in FIG. 17A. FIG. 17A shows six light panels 100, arranged in a 2×3 array; however, this is not a limitation of the present invention, and in other embodiments other array geometries or layouts may be used. For example, light panels 100 in FIG. 17A are tiled together such that the edges of adjacent light panels 100 meet or are relatively close together, for example such that the LEE pitch between two adjacent light panels 100 (that is the LEE pitch that spans across the edges of two adjacent light panels 100) is the same or substantially the same as the LEE pitch within a single light panel 100. However, this is not a limitation of the present invention, and in other embodiments light panels 100 may be spaced apart, for example in a substantially regular pattern, for example as shown in FIG. 17B or in an arbitrary pattern, for example as shown in FIG. 17C. Electrical connections between light panels 100 are not shown for clarity in FIGS. 17A-17C. While FIGS. 17A-17C depict light panels 100, this is not a limitation of the present invention, and in other embodiments similar configurations may be formed using light sheets 110.

In various embodiments of the present invention, the means for electrical coupling to or between light panels 100 or light sheets 110 may include or consist essentially of a vertical connector, in which the connection mechanism is activated or deactivated by movement of at least one connector component in a direction substantially perpendicular to the surface of the light panel in the region of the connector. FIG. 18A shows one embodiment of a vertical connector that includes or consists essentially of a pin 1810 that mates with a socket 1820. In various embodiments of the present invention, pin 1810 is electrically coupled and/or mounted on conductive trace 210. Wire 1830 is electrically coupled to socket 1820 and may be used to provide electrical coupling (i.e., provide electrical power and/or communication and/or control signals) through socket 1820 and pin 1810 to one or more conductive traces 210 disposed over substrate 265. FIG. 18B shows another embodiment of the present invention in which the vertical socket 1820 fits over pin 1810 and a portion of pin 1810 protrudes through and is visible over the socket 1820 when the socket 1820 is in place. Such connectors may include, for example the 400 series connectors available from Bender & Wirth GmbH & Co of Kierspe, Germany.

FIG. 18C shows another embodiment of the present invention that features a snap connector including or consisting essentially of at least two parts, identified in FIG. 18C as a button 1840 and a button socket 1850. Button 1840 and button socket 1850 are shown as disengaged in FIG. 18C and engaged in FIG. 18D. In some embodiments of the present invention, button 1840 is electrically coupled and/or mounted on a conductive trace 210. As with the vertical connector shown in FIG. 18A, button socket 1850 may be electrically coupled to one or more wires 1830. In various embodiments, light panels may be electrically coupled by a jumper 1860 between two connectors, as shown in FIG. 18D.

In various embodiments of the present invention, button socket 1850 may be mounted on or to one light sheet 110, and button 1840 may be mounted on or to a second light sheet 110′, permitting direct connection between two light panels, as shown in FIG. 18E. In various embodiments of the present invention, button 1840 and button socket 1850 may be formed on opposite sides of the two light sheets, for example either the button 1840 or button socket 1850 may be mounted on the front surface of one light sheet while the mating connector may be mounted on the back surface of a second light sheet. For example, in the structure shown in FIG. 18E, button 1840 is mounted on the front side of light sheet 110 and button socket 1850 is mounted on the back side of light sheet 110′. As shown in FIG. 18E, a via 1860 electrically couples button socket 1850 to conductive trace 210′ through substrate 265′. In various embodiments of the present invention, via 1860 may include or consist essentially of a rivet, a staple, a crimp or piercing connector, or the like. In various embodiments of the present invention, button 1840 and button socket 1850 may be formed on the same side of the light sheet; for example, as shown in FIG. 18F, button 1840 and button socket 1850 are formed on the same side (e.g., front side) of light sheets 110 and 110′, and a portion of light panel 110′ is folded over to facilitate connection of button socket 1850 to button 1840.

In various embodiments of the present invention, the snap connector may include or consist essentially of a 9V battery connector. 9V battery connectors have male and female components, as shown in FIGS. 18G and 18H respectively.

In various embodiments of the present invention, the snap connectors may be electrically coupled to conductive trace 210 and/or mechanically coupled to conductive trace 210 and/or substrate 265 using a variety of means, for example solder, conductive adhesive, anisotropic conductive adhesive, eyelets, rivets, crimp connectors, piercing connectors, or the like. The method of attachment of the snap connectors to a light sheet or light panel is not a limitation of the present invention.

FIG. 19A shows one embodiment of a light sheet 110 that features LEEs 230 and connectors 1910, 1910′, 1920, and 1920′ disposed on substrate 265. Conductive traces providing electrical coupling between LEEs 230 and current control elements and power conductors 1960 and 1970 are not shown for clarity in FIG. 19A. In various embodiments of the present invention, connectors 1910, 1910′, 1920, and 1920′ may include, consist essentially of, or consist of vertical connectors or snap connectors; however, this is not a limitation of the present invention and in other embodiments other forms of connectors may be used. In various embodiments of the present invention, connectors 1910 and 1910′ may include or consist essentially of female 9V battery connectors as shown in FIG. 18H, and connectors 1920 and 1920′ may include or consist essentially of male 9V battery connectors as shown in FIG. 18G. In the embodiment shown in FIG. 19A, the connectors are all disposed on the same side of light sheet 110; however, this is not a limitation of the present invention, and in other embodiments various connectors may be formed on different sides of light sheet 110, for example as discussed in reference to FIG. 18E.

In various embodiments, the connectors may be used to provide power to the light sheet. For example, in various embodiments of the present invention, power to light sheet 110 may be provided through connectors 1910′ and 1920′. For example, in various embodiments, connector 1910′ may be used for the positive power supply connection and connector 1920′ may be used for the negative or ground power supply connection; however, this is not a limitation of the present invention, and in other embodiments other configurations for powering the light sheet may be utilized.

In various embodiments of the present invention, for example as shown in FIG. 19A, connectors 1920′ and 1910 may be electrically coupled together by an electrical trace 1960 (shown in FIG. 19A as a dashed line), and connectors 1910′ and 1920 may be electrically coupled together by a conductive trace 1970 (shown in FIG. 19A as a dashed line). In various embodiments of the present invention, multiple light sheets 110 may be electrically coupled together, for example by connecting connector 1910 on a first light sheet to connector 1920′ on a second light sheet and by connecting connector 1920 on a first light sheet to connector 1910′ on a second light sheet.

In various embodiments of the present invention, one or more connectors may be positioned on a tab extending out from the main portion of the light sheet, for example tab 1930 as shown in FIG. 19A. In various embodiments of the present invention, a portion of tab 1930 may be folded over (see, e.g., folded portion 1931 in FIG. 19B), for example as discussed in reference to FIG. 18F, to facilitate connection to another light sheet. FIG. 19B shows a schematic of a portion of a tab 1930 containing connector 1920 disposed on a partially folded-over portion 1931, while FIG. 19C shows a schematic of a portion of tab 1930 containing connector 1920 in a completely or substantially completely folded-over position. In various embodiments of the present invention, the folded-over portion may be held in place by an adhesive, glue, tape or the like, for example adhesive 1980 in FIG. 19B. In various embodiments of the present invention, a portion of connector 1920 may extend through a portion of folded portion 1931 or portions of both tab 1930 and folded portion 1931. FIG. 19D shows an example of an embodiment of the present invention featuring light sheet 110 having a tab 1930 with a portion 1931 folded over prior to the connector being disposed on the sheet. In this example, the connector includes or consists essentially of two parts, identified as a back connector part 1921 and a front connector part 1922, which are mated through a hole 1923. In this example, hole 1923 is formed through both tab 1930 and the folded over portion of tab 1931 prior to completing formation of the connector. However, this is not a limitation of the present invention, and in other embodiments, one or both of back connector part 1921 and front connector part 1922 may pierce or otherwise form a hole in tab 1930 and/or folded portion of the tab 1931 during placement of the connector. In the example shown in FIG. 19D, mating of back connector part 1921 and front connector part 1922 may include mechanically bringing the two parts together and deforming a portion of one or both connector parts to bind the two portions together. The structure of the connector and/or the method of forming a connector from two or more connector parts are not limitations of the present invention.

In various embodiments of the present invention, a folded portion 1990 of the light sheet may be folded over, for example as shown in FIG. 19E. In various embodiments, all or a portion of power conductor 210 or 220, for example as shown in FIG. 2C, may be disposed on or in the folded portion 1990. In various embodiments, the placement of all or a portion of power conductor 210 or 220 on folded portion 1990 may be used to decrease the resistance per unit length of the power conductor, for a given width light sheet, by increasing the effective width of power conductor 210 or 220. As shown in FIG. 19E, light sheet 100 has a width 1992, not including folded portions 1990. Folded portions 1990 each have a width 1997. FIG. 19F shows a detailed schematic of a portion of light sheet 110, showing a comparison of light sheet 110 with and without a folded portion 1990. Light sheet 110 without folded portion 1990 has power conductor 210 having a width 1994. Light sheet 110 with folded portion 1990 has power conductor 210′ having an additional width 1996, for a total width equal to the sum of width 1994 and width 1996. For a power conductor 210 having a substantially constant thickness and resistivity, the resistance per unit length is inversely proportional to the width of power conductor 210. For the example shown in FIG. 19E, the conductance of power conductor 210′ (including portions 1994 and 1996) is (1994+1996)/1994 times that of power conductor 210 (having width 1994). In various embodiments of the present invention, folded portion 1990 may have a width 1996 in the range of about 2 mm to about 50 mm. In various embodiments of the present invention, power conductor 210 may have a width of 1994 of about 3 mm and power conductor 210′ may have a width (1994+1996) of about 9 mm, resulting in power conductor 210′ having a resistance about 3× lower than that of power conductor 210. In various embodiments of the present invention, power conductor 210′ may have a resistance in the range of about 1.5 to about 10 times lower than that of power conductor 210. While FIG. 19F shows one folded portion 1990, this is not a limitation of the present invention, and in other embodiments light sheet 110 may have multiple folded portions. For example FIG. 19G shows light sheet 110 having two folded portions 1990 and 1990′. However, this is not a limitation of the present invention, and in other embodiments light sheet 110 may have more than two folded portions. While FIG. 19G shows the folds in a fan-fold configuration, this is not a limitation of the present invention and in other embodiments the folding configuration may be different. For example in various embodiments the folds may be rolled-over or folded over, as shown in FIG. 19I, or may have other fold configurations or combinations of configurations. In various embodiments, the folded portions or parts of the folded portions may be adhered or fastened to each other or to the unfolded part of the light sheet, for example using glue, adhesive, tape, lamination, staples, rivets, or the like.

In various embodiments of the present invention, light sheets 110 having folded portions 1990 may be combined with frame elements, for example frame elements 120, 120′. In various embodiments of the present invention, folded portion 1990 of light sheet 110 may be folded or wrapped around a portion of frame element 120 or 120′ as shown in FIG. 19H; however, this is not a limitation of the present invention, and in other embodiments folded portion 1990 of light sheet 110 may be disposed under or over frame element 120, 120′, or light sheet 110 with one or more folded portions 1990 may be utilized without any frame elements.

In various embodiments of the present invention, a portion of light sheet 110 may be adhered or attached to frame 120 or to a portion of frame 120, for example using adhesive, glue, tape, double-sided tape, or the like. For example, in various embodiments a portion of light sheet 110 may be adhered to a portion of frame 120, for example all, substantially all or a portion of the top and/or the bottom and/or the sides of frame 120 may be adhered to light sheet 110. In various embodiments of the present invention, a lighting system may include or consist essentially of an assemblage of multiple light sheets 110 and/or light panels 100 and an associated connector system. In various embodiments of the present invention, the connector system utilizes the same type of connectors, or snap connectors or 9V battery connectors that are used on light sheets 110 and/or light panels 100.

While FIG. 19F shows portions 1994 and 1996 having the same or substantially the same shape, this is not a limitation of the present invention, and in other embodiments they may have different shapes. For example, FIG. 19J shows an example of an embodiment of the present invention in which portion 1994 has a different shape than that of portion 1996. While FIG. 19F shows portions 1994 and 1996 as one contiguous area, this is not a limitation of the present invention, and in other embodiments portions 1994 and 1996 may have one or more spaces between them or gaps 1997 (areas not containing the electrically conductive trace material) in them, for example as shown in FIGS. 19K and 19L.

In various embodiments the light panel, for example as shown schematically in FIGS. 1A, 2B, 19H, and other figures herein, may have a thickness in the range of about 0.25 mm to about 20 mm, or in the range of about 0.4 mm to about 5 mm.

FIGS. 20A and 20B show two types of light sheets or light panels 2010 and 2020, respectively, in accordance with embodiments of the present invention. Panel 2010 has tabs 1930, each of which has a connector disposed thereon. Panel 2020 does not have tabs 1930, and the connectors are disposed on the main panel body of the light panel or light sheet (e.g., near the periphery and/or corners of the panel or sheet). In this embodiment of the present invention, the connector system includes or consists essentially of two mating connectors 2030 and 2040. (Physically similar or identical connectors, but formed in different locations on the light sheet or light panel are identified by one or more apostrophes, for example 2030 and 2030′ are the same physical type of connector, but disposed in different locations on the light sheet or light panel.) Connectors 2030 and 2040 mate to each other and in some embodiments of the present invention are polarized (e.g., one connector is male and the other is female) to prevent misconnection of the light panels or light sheets. However, this is not a limitation of the present invention, and in other embodiments connectors 2030 and 2040 may not be polarized. In the schematics of FIGS. 20A-20C, connectors 2030 are identified by the grey filled-in circles, and connectors 2040 are identified by the white filled-in circles. In various embodiments of the present invention, when multiple light sheets or light panels are connected, connector 2040 is electrically coupled to connector 2030′ and connector 2030 is electrically coupled to connector 2040′, for example as discussed in reference to FIG. 19A. This permits multiple light panels or light sheets to be electrically coupled through these connectors, for example as discussed in reference to FIG. 20C below.

In various embodiments of the present invention, other connector configurations may be utilized, for example a portion of one sheet may overlap a portion of an adjacent sheet to permit alignment and mating of the electrical connectors. In various embodiments of the present invention, the electrical connectors may be mated by coupling in a direction parallel to or substantially parallel to the surface of the light sheet.

FIG. 20C shows an embodiment of a lighting system of the present invention that is partially assembled, and that includes or consists essentially of three panels 2010, 2010′, and 2010″ and one panel 2020. Panels 2010′ and 2010″ have been electrically coupled together. Panel 2010 is awaiting assembly, which is completed by connecting connector 2040′ on panel 2010 to connector 2030′ on panel 2010′ and connecting connector 2030 on panel 2010 to connector 2040 on panel 2010′. Panel 2020 is awaiting assembly into the lighting system, which is completed using jumpers 2050, 2050′ (jumper 2050′ has already been connected) by connecting connector 2030′″ on jumper 2050 to connector 2040″ on panel 2010″ and connecting connector 2040′″ on jumper 2050 to connector 2030″ on panel 2020. Jumper 2050 may have any length and may be straight, as shown in FIG. 20C, or may be curved or have any shape. While jumper 2050 is shown in FIG. 20C as connecting a 2010-type panel to a 2020-type panel, this is not a limitation of the present invention, and in other embodiments one or more jumpers 2050 may connect two 2010-type panels (i.e., panels having one or more protruding tabs) or two 2020-type panels (i.e., panels lacking protruding tabs) or any other style or configuration of panels. In various embodiments of the present invention, the connectors on the left side (top and bottom) of each light sheet or light panel are electrically coupled together and the connectors on the right side (top and bottom) of each light sheet or light panel are electrically coupled together, permitting multiple light sheets or light panels to be powered by connection from one end of the array of light panels or light sheets (i.e., from one end of the assembled lighting system). The order of assembly of the components with reference to FIG. 20C (including but not limited to light sheets, light panels, and jumpers) is one example of how these components may be assembled. In other embodiments of the present invention, the assembly order may be different and/or other components may be utilized.

In various embodiments of the present invention, jumper 2050 may be constructed in a similar fashion to the light panel, while in other embodiments, jumper 2050 may have a different construction from that of the light panel. In various embodiments of the present invention, jumper 2050 may include or consist essentially of one or more wires or wire harnesses with connectors. In various embodiments of the present invention, jumper 2050 may include or consist essentially of a flexible substrate having conductive traces disposed on the substrate and connectors electrically coupled to the conductive traces (i.e., in the style of light sheets as described herein).

In various embodiments of the present invention, a light sheet or light panel may have one or more connector wires directly attached to one or more power conductors or other conductive elements. In such embodiments, the other end of the wire (the end not electrically coupled to a portion of the light sheet or light panel) may be a flying lead, i.e., just the wire, or may be terminated with a connector, or may be integrated into a wiring harness, or may be contacted by other means.

In various embodiments of the present invention, jumpers may be used to electrically couple one or more light panels or light sheets to a power bus or power supply. FIG. 21A shows a lighting system including or consisting essentially of nine light panels or light sheets 2010. The nine light panels have been connected into three vertically oriented groups of three panels each, and the system is ready for connection to a power supply. While the system of FIG. 21A shows a lighting system including or consisting essentially of nine light sheets or light panels, this is not a limitation of the present invention, and in other embodiments the lighting system may have fewer or more light sheets or light panels.

In various embodiments of the present invention, a power bus or power wiring harness 2110 may include or consist essentially of one or more power conductors, for example power conductors 2120 and 2130, and one or more connectors, for example connectors 2030′″ and 2040′ (other connectors are shown in FIG. 21A, but not identified with separate identification numbers). In various embodiments, connector 2030′ is electrically coupled to power conductor 2120 and connector 2040′″ is electrically coupled to power conductor 2030 (other connectors are shown as electrically coupled, but not identified in FIG. 21A with separate identification numbers). To continue assembly of the lighting system, connector 2030′″ on power bus 2110 is connected to connector 2040 on jumper 2050′, connector 2040′ on power bus 2110 is electrically connected to connector 2030 on jumper 2050, connector 2030′ on jumper 2050′ is electrically connected to connector 2040″ on panel 2010′, and connector 2040′ on jumper 2050 is electrically connected to connector 2040″ on panel 2010′. While the system shown in FIG. 21A uses light panels or light sheets with protruding tabs, this is not a limitation of the present invention, and in other embodiments tab-less panels may be used or a mixture tabbed and tab-less panels may be used, or any other type or style of light sheets or panels may be used. While the system shown in FIG. 21A shows panels 2010 as close coupled, i.e., all of the panels are connected together with relatively little space between each panel, both in the horizontal and vertical directions, this is not a limitation of the present invention, and in other embodiments, additional space between adjacent panels, for example in the horizontal direction or vertical direction or both directions may be part of the present invention.

In various embodiments of the present invention, the light sheets or light panels are configured and positioned such that the distance between adjacent LEEs between adjacent light sheets or light panels is the same or substantially the same as the distance between adjacent LEEs on one light sheet or light panel, i.e., the pitch between LEEs on a light panel or light sheet is the same or substantially the same as the pitch between adjacent LEEs across the joint or interface between two adjacent light sheets or light panels. In various embodiments of the present invention, the lighting system includes or consists essentially of multiple light panels or light sheets and the pitch or distance between adjacent LEEs is the same, independent of whether the LEEs are on one light sheet or light panel or on separate light panels or light sheets. In various embodiments of the present invention, the LEEs are spaced in a rectangular array on the light sheet or light panel with a first pitch in a first direction and a second pitch in a second direction that is substantially perpendicular to the first direction, and the system includes or consists essentially of multiple light sheets or light panels, and the pitch in the first direction between adjacent light sheets is the same as the first pitch on the light sheet or light panel, and the pitch in the second direction between adjacent light sheets is the same as the second pitch on the light sheet or light panel. For example, in various embodiments, the pitch between all LEEs in a system including multiple light panels, for example the system shown in FIG. 21A, is the same or substantially the same.

While the lighting system shown in FIG. 21A includes nine light panels or light sheets 2010, this is not a limitation of the present invention, and in other embodiments fewer or more light panels and/or light sheets 2010 may be utilized. In various embodiments of the present invention, a lighting system may include or consist essentially of at least 50 light panels and/or light sheets, or at least 100 light panels and/or light sheets, or at least 500 light sheets and/or light panels, or at least 5000 light sheets and/or light panels

FIG. 21B shows an embodiment of a lighting system of the present invention similar to that of the lighting system of FIG. 21A; however, in the system of FIG. 21B, power bus or power wiring harness 2111 differs from power bus or power wiring harness 2110 by elimination of jumpers 2050. Jumpers 2050 are replaced by tabs or extensions 2140 on which are disposed the connectors that connect to a connector on a light sheet or light panel. In various embodiments of the present invention, tabs or extensions 2140 may each include one connector; however, this is not a limitation of the present invention, and in other embodiments a tab or extension 2140 may include more than one connector, as shown by tab or extension 2150. While tab or extension 2150 includes two connectors, this is not a limitation of the present invention, and in other embodiments tab or extension 2150 may include more than two connectors. In various embodiments of the present invention, power bus or power wiring harness 2111 does not include tabs or extensions 2140 or 2150, and the connectors are formed on the body of power bus or power wiring harness 2111, as shown in FIG. 21C. In various embodiments of the present invention the power bus or power wiring harness includes or consists essentially of one or more wires, optionally bundled together with connectors wired to the main power lines in the power bus.

In various embodiments of the present invention, the connectors on the left side (top and bottom) of each light sheet or light panel are electrically coupled together and the connectors on the right side (top and bottom) of each light sheet or light panel are electrically coupled together, permitting multiple light sheets or light panels to be powered by connection from one end of the array of light panels or light sheets. For example, in the lighting system of FIG. 21B, a power supply 2170 provides power through power bus 2111 to the bottom three light panels. This power is then conveyed through the bottom light sheet or light panel to the light sheet or light panel to which it is electrically coupled, and so on. For example, light panel 2010 is powered from power bus 2111, light panel 2010′ is provided power from light panel 2010, and light panel 2010″ is provided power from light panel 2010′. In various embodiments of the present invention, this permits powering or energizing of large linear assemblies of light panels or light sheets with only one power connection, and in some embodiments from only one end of the assembly. In various embodiments of the present invention, different configurations of connection of two or more connectors may be utilized.

In the example in FIG. 21B, power bus 2111 is electrically coupled to power supply 2170. In various embodiments of the present invention, power supply 2170 provides power to energize light panels 2010. In various embodiments of the present invention, power supply 2170 provides a constant voltage power to power bus 2111; however, this is not a limitation of the present invention, and in other embodiments power supply 2170 may provide constant current, AC-based power, or any other type of power. In various embodiments of the present invention, power supply 2170 is energized from a mains power supply, for example an AC mains power source; however, this is not a limitation of the present invention, and in other embodiments power supply 2170 may be energized from a battery or batteries, rechargeable battery or batteries, photovoltaic generation systems, wind generation systems, gas or other fuel based generator systems, energy harvesting systems, another power supply, or other power sources. In various embodiments of the present invention, power supply 2170 may provide a constant voltage that is modulated, for example using pulse-width modulation (PWM), to permit dimming of light-emitting elements on light panels 2010; however, this is not a limitation of the present invention, and in other embodiments dimming may be accomplished by other means, for example by modification of the current to each light panel, modification of the voltage to each light panel, or by other means.

In various embodiments of the present invention, a power bus or power wiring harness 2111 or 2112 may also support control or communication signals to the light sheets or light panels, or from the light sheets or light panels, for example to provide control and/or communication signals between a power source, for example power supply 2170 and light panels 2010. In various embodiments, control or communication signals may be used to selectively energize or de-energize individual or groups of light panels or light sheets in a lighting system, or to selectively energize or de-energize portions of individual or groups of light panels or light sheets or to modify the intensity of light emitted by individual or groups of light panels or light sheets in a system, or to modify the intensity of light emitted by portions of individual or groups of light panels or light sheets, or to modify other optical characteristics of individual or groups of light panels or light sheets or portions of individual or groups of light panels or light sheets, for example correlated color temperature (CCT), color rendering index (CRI), R9, spectral power distribution, light distribution pattern, or the like.

FIG. 21C shows an embodiment of the present invention in which a power bus or power wiring harness 2112 without tabs or extensions 2140 or 2150 is connected to light panels or light sheets 2010. In the lighting system of FIG. 21C, the vertical columns of light panels or light sheets are spaced apart from each other, in contrast to the system of FIG. 21B, in which the light panels or light sheets are positioned substantially next to each other. Furthermore, in the system of FIG. 21C, power bus or power wiring harness 2112 extends beyond the limits of the figure, and may provide power to one or more additional groups of light sheets or light panels. The number of groups of light sheets or light panels powered by the power bus or power wiring harness is not a limitation of the present invention.

FIG. 21D shows a schematic of another embodiment of the present invention in which power is supplied to multiple columns of light panels or light sheets from one end of the assembly. Power supply 2170 supplies power to light sheet 2010, which provides power to light sheet 2010′. Power is then conveyed from light sheet 2010′ through power bus 2112 to light sheet 2010″, which provides power to light sheet 2010′. Power is then conveyed from light sheet 2010′ through power bus 2113 to the next array of light sheets (not shown).

FIG. 21E shows a schematic of another embodiment of the present invention in which the connectors are grouped on one tab, with each tab having multiple connectors. For example, power bus 2111 has one tab connecting to each light panel, for example tab 2141 connecting to panel 2010. In various embodiments, one tab may include two or more connectors, while in other embodiments each connector may include or consist essentially of multiple separate electrical conductors.

Power buses or power wiring harnesses may incorporate one or more tabs or no tabs, and various types of power buses or power wiring harnesses as well as combinations of various types of power buses or power wiring harnesses are within the scope of this invention.

While the systems shown in FIGS. 19A, 19H, 20A-20C, and 21A-21C depict substantially square light panels or light sheets, this is not a limitation of the present invention, and in other embodiments light panels or light sheets may have other shapes, for example rectangular, hexagonal, triangular, parallelogram, or any arbitrary shape. While FIGS. 21A-21C show square arrays of light sheets or light panels, this is not a limitation of the present invention, and in other embodiments the light sheets or light panels may be configured or positioned in a rectangular array, a hexagonal array, a triangular array, or any other array, whether periodic or not.

FIG. 21F shows an embodiment of a lighting system of the present invention including or consisting essentially of light panels 2010 attached to a support 2190 and covered or partially covered by an optic 2185 (the details of support 2190 and of optic 2185 are not shown for clarity, nor are they limitations of the present invention). As shown in FIG. 21F, optic 2185 is spaced apart from light panels 2010 by a spacing 2180. In various embodiments of the present invention, optic 2185 may be in contact with light panel 2010 or substantially in contact with light panel 2010, while in other embodiments optic 2185 may be in contact or substantially in contact with the LEEs on light panel 2010, or may be spaced apart from light panel 2010 as shown in FIG. 21F. In various embodiments of the present invention, spacing 2180 may be in the range of about 0.5× to about 5×, or in the range of about 1× to about 2×, the spacing or pitch of LEEs on light panel 2010. In various embodiments of the present invention, spacing 2180 may be in the range of about 5 mm to about 500 mm, or in the range of about 10 mm to about 100 mm. In various embodiments of the present invention, support 2190 may include or consist essentially of a wall, ceiling, floor, column, sub-structure, substrate, or other feature to which light panel or panels 2010 may be attached or mounted. In various embodiments of the present invention, optic 2185 may include or consist essentially of a lens, a diffuser, a refractive optic, a reflective optic, a Fresnel optic, a fabric, a translucent material such as plastic or stone, a graphic panel, a membrane or the like. In various embodiments of the present invention, optic 2185 may include or consist essentially of a plurality of optical elements, for example as described in U.S. patent application Ser. No. 13/693,632, filed on Dec. 4, 2012, the entire disclosure of which is incorporated by reference herein. In various embodiments of the present invention, optic 2185 may include or consist essentially of glass, stone, plastic, fabric, foam, paper, or the like.

In various embodiments of the present invention, the total thickness 2181 of the lighting system shown in FIG. 21F, i.e., the distance between the back of light panel 2010 to the front of optic 2185, may be in the range of about 1× to about 5× the spacing or pitch of LEEs on light panel 2010, or in the range of about 1.5× to about 4× the spacing or pitch of LEEs on light panel 2010. In various embodiments of the present invention, a total thickness 2181 of the lighting system shown in FIG. 21F may be in the range of about 1 cm to about 10 cm, or in the range of about 1.5 cm to about 5 cm.

While a number of the examples described herein include or consist essentially of one or more flexible light sheets and one or more frame elements, this is not a limitation and in other embodiments frame elements may be eliminated, resulting in light panels including or consisting essentially of one or more flexible light sheets with no frame elements.

While a number of the examples described herein utilize a constant-voltage drive system for powering one or more light sheets or light panels, this is not a limitation of the present invention, and in other embodiments other modes of energizing one or more light sheets or light panels may be utilized, for example constant-current or AC drive or other modes. In some embodiments of the present invention, the mode of powering the light sheets or light panels may determine the type, number, or need for current control elements on each light sheet or light panel. For example, in some embodiments of the present invention, no current control elements may be required on the light panel or light sheet, for example if using a constant-current drive mode.

While a number of examples presented herein utilize 9V battery connectors for connectorized panels (i.e., panels having one or more connectors), this is not a limitation of the present invention and in other embodiments other types of connectors may be utilized. For example, such connectors may include commercially available plug and jack or male and female connectors, polarized or unpolarized connectors, or connectors which on one or more ends are connected to a light sheet or light panel by wires.

As utilized herein, the term “light-emitting element” (LEE) refers to any device that emits electromagnetic radiation within a wavelength regime of interest, for example, visible, infrared or ultraviolet regime, when activated, by applying a potential difference across the device or passing a current through the device. Examples of light-emitting elements include solid-state, organic, polymer, phosphor-coated or high-flux LEDs, laser diodes or other similar devices as would be readily understood. The emitted radiation of an LEE may be visible, such as red, blue or green, or invisible, such as infrared or ultraviolet. An LEE may produce radiation of a continuous or discontinuous spread of wavelengths. An LEE may feature a phosphorescent or fluorescent material, also known as a light-conversion material (or a wavelength-conversion material, or a phosphor), for converting a portion of its emissions from one set of wavelengths to another. In some embodiments, the light from an LEE includes or consists essentially of a combination of light directly emitted by the LEE and light emitted by an adjacent or surrounding light-conversion material. An LEE may include multiple LEEs, each emitting essentially the same or different wavelengths. In some embodiments, a LEE is an LED that may feature a reflector over all or a portion of its surface upon which electrical contacts are positioned. The reflector may also be formed over all or a portion of the contacts themselves. In some embodiments, the contacts are themselves reflective. Herein “reflective” is defined as having a reflectivity greater than 65% for a wavelength of light emitted by the LEE on which the contacts are disposed. In some embodiments, an LEE may include or consist essentially of an electronic device or circuit or a passive device or circuit. In some embodiments, an LEE includes or consists essentially of multiple devices, for example an LED and a Zener diode for static-electricity protection. In some embodiments, an LEE may include or consist essentially of a packaged LED, i.e., a bare LED die encased or partially encased in a package. In some embodiments, the packaged LED may also include a light-conversion material. In some embodiments, the light from the LEE may include or consist essentially of light emitted only by the light-conversion material, while in other embodiments the light from the LEE may include or consist essentially of a combination of light emitted from an LED and from the light-conversion material. In some embodiments, the light from the LEE may include or consist essentially of light emitted only by an LED.

One or more non-LEE devices such as Zener diodes, transient voltage suppressors (TVSs), varistors, etc., may be placed on each light sheet to protect the LEEs 230 from damage that may be caused by high-voltage events, such as electrostatic discharge (ESD) or lightning strikes. In one embodiment, conductive trace segments shown in FIG. 2B between the LEE strings 250 may be used for placement of a single protection device per light sheet, where the device spans the positive and negative power traces, for example power conductors 210, 220. These trace segments also serve to provide a uniform visual pattern of lines in the web direction, which may be more aesthetically pleasing than a light sheet with noticeable gaps between LEE strings 250. In a more general sense, in addition to conductive traces 260 that are part of string 250, additional conductive traces 260 that may or may not be electrically coupled to other strings 250 and/or power conductors 210, 220 may be formed on substrate 265, for example to provide additional power conduction pathways or to achieve a decorative or aesthetically pleasing look to the pattern on the light sheet or to provide a communication pathway to one or more CEs 240, for example to provide a control signal to the one or more CEs 240. These trace segments also serve to provide a uniform visual pattern of lines in the web direction, which may be more aesthetically pleasing than a light sheet with noticeable gaps between LEE strings 250.

In one embodiment, an LEE 230 includes or consists essentially of a bare semiconductor die (such as an LED), while in other embodiments LEE 230 includes or consists essentially of a packaged LED.

In some embodiments, LEE 230 may include or consist essentially of a “white die” that includes an LED that is integrated with a light-conversion material (e.g., a phosphor) before being attached to the light sheet, as described in U.S. patent application Ser. No. 13/748,864, filed Jan. 24, 2013, or U.S. patent application Ser. No. 13/949,543, filed Jul. 24, 2013, the entire disclosure of each of which is incorporated by reference herein.

In some embodiments, LEEs 230 may emit light in a relatively small wavelength range, for example having a full width at half maximum in the range of about 20 nm to about 200 nm. In some embodiments, all LEEs 230 may emit light of the same or substantially the same wavelength, while in other embodiments different LEEs 230 may emit light of different wavelengths. In some embodiments LEEs 230 may emit white light, for example that is perceived as white light by the eye. In some embodiments, the white light may be visible light with a spectral power distribution the chromaticity of which is close to the blackbody locus in the CIE 1931 xy or similar color space. In some embodiments, white light has a color temperature in the range of about 2000 K to about 10,000 K. The emission wavelength, full width at half maximum (FWHM) of the emitted light or radiation or other optical characteristics of LEEs 230 may not be all the same and are not a limitation of the present invention.

Substrate 265 may include or consist essentially of a semicrystalline or amorphous material, e.g., polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate, polyethersulfone, polyester, polyimide, polyethylene, fiberglass, FR4, metal core printed circuit board, (MCPCB), and/or paper. Substrate 265 may include multiple layers, e.g., a deformable layer over a rigid layer, for example, a semicrystalline or amorphous material, e.g., PEN, PET, polycarbonate, polyethersulfone, polyester, polyimide, polyethylene, and/or paper formed over a rigid substrate for example comprising, acrylic, aluminum, steel and the like. Depending upon the desired application for which embodiments of the invention are utilized, substrate 265 may be substantially optically transparent, translucent, or opaque. For example, substrate 265 may exhibit a transmittance or a reflectivity greater than 70% for optical wavelengths ranging between approximately 400 nm and approximately 700 nm. In some embodiments substrate 265 may exhibit a transmittance or a reflectivity of greater than 70% for one or more wavelengths emitted by LEE 230. Substrate 265 may also be substantially insulating, and may have an electrical resistivity greater than approximately 100 ohm-cm, greater than approximately 1×10⁶ ohm-cm, or even greater than approximately 1×10¹⁰ ohm-cm. In some embodiments substrate 265 may have a thickness in the range of about 10 μm to about 500 μm.

Conductive elements, e.g., power conductors 210, 220 and conductive traces 260, may be formed via conventional deposition, photolithography, and etching processes, plating processes, lamination, lamination and patterning, evaporation sputtering or the like or may be formed using a variety of different printing processes. For example, power conductors 210, 220 and conductive traces 260 may be formed via screen printing, flexographic printing, ink-jet printing, and/or gravure printing. Power conductors 210, 220 and conductive traces 260 may include or consist essentially of a conductive material (e.g., an ink or a metal, metal film or other conductive materials or the like), which may include one or more elements such as silver, gold, aluminum, chromium, copper, and/or carbon. Power conductors 210, 220 and conductive traces 260 may have a thickness in the range of about 50 nm to about 1000 In some embodiments, the thickness of power conductors 210, 220 and conductive traces 260 may be determined by the current to be carried thereby. While the thickness of one or more of power conductors 210, 220 and conductive traces 260 may vary, the thickness is generally substantially uniform along the length of the trace to simplify processing. However, this is not a limitation of the present invention, and in other embodiments the thickness and/or material of power conductors 210, 220 and conductive traces 260 may vary. In some embodiments, all or a portion of power conductors 210, 220 and conductive traces 260 may be covered or encapsulated. In some embodiments, a layer of material, for example insulating material, may be formed over all or a portion of power conductors 210, 220 and conductive traces 260. Such a material may include, e.g., a sheet of material such as used for substrate 265, a printed layer, for example using screen, ink jet, stencil or other printing means, a laminated layer, or the like. Such a printed layer may include, for example, an ink, a plastic and oxide, or the like. The covering material and/or the method by which it is applied is not a limitation of the present invention.

In one embodiment, the conductive traces 260 are formed with a gap between adjacent conductive traces 260, and LEEs 130 and CEs 240 are electrically coupled to conductive traces 260 using conductive adhesive, e.g., an isotropically conductive adhesive and/or an ACA. ACAs may be utilized with or without stud bumps and embodiments of the present invention are not limited by the particular mode of operation of the ACA. For example, the ACA may utilize a magnetic field rather than pressure (e.g., the ZTACH ACA available from SunRay Scientific of Mt. Laurel, N.J., for which a magnetic field is applied during curing in order to align magnetic conductive particles to form electrically conductive “columns” in the desired conduction direction). Furthermore, various embodiments utilize one or more other electrically conductive adhesives, e.g., isotropically conductive adhesives, non-conductive adhesives, in addition to or instead of one or more ACAs. In other embodiments, LEEs 230 and CEs 240 may be attached to and/or electrically coupled to conductive traces 260 by other means, for example solder, reflow solder, wave solder, wire bonding, or the like. The method by which LEEs 230 and CEs 240 are attached to conductive traces 260 is not a limitation of the present invention.

CE 240 may be one component or multiple active and/or passive components. In one embodiment, power conductors 210, 220 provide a DC voltage or substantially DC voltage and CE 240 includes or consists essentially of a resistor, e.g. a current-limiting resistor. The choice of the resistance value may be a trade-off between a number of parameters and characteristics that may include, e.g., efficiency and current stability. In general, a larger resistance will result in reduced efficiency but greater current stability, while a smaller resistance will result in increased efficiency but reduced current stability. Variations in the current may result from variations in the input voltage (for example across power conductors 210, 220), variations in forward voltage of the LEEs 230 within the string, variations in the value of the current-limiting resistor, variations in current that may occur if one or more LEEs 230 in the string become short-circuited or the like. In the case of CE 240 including or consisting essentially of a resistor, in some embodiments CE 240 is a discrete resistor formed within or on conductive traces 260, such as a chip resistor, a bare-die resistor or surface mount device (SMD) resistor.

As discussed above, in embodiments where CE 240 includes or consists essentially of a resistor, there may be trade-offs between efficiency and current stability. While such trade-offs may be acceptable in certain products, other products may require relatively better current stability at higher efficiencies, and in these cases CE 240 may include or consist essentially of multiple components or a circuit element, as discussed above. In some embodiments CE 240 includes or consists essentially of a field-effect transistor (FET) and a resistor. In another embodiment CE 240 includes or consists essentially of two bipolar junction transistors (BJTs) and two resistors.

In general, the efficiency and current stability increase with the number of components, as does the cost. In some embodiments where a CE 240 includes or consists essentially of multiple components, the components may be in discrete form (i.e., each component individually electrically coupled to conductive traces 260) or in hybrid form (where multiple separate components are mounted on a submount, which is then electrically coupled to conductive traces 260), or in monolithic form (where multiple components are integrated on a semiconductor chip, for example a silicon-based or other semiconductor-based integrated circuit). In some embodiments, CEs 240 may be in bare-die form, while in other embodiments CEs 240 may be packaged or potted or the like. In some embodiments, a CE 240 may include or consist essentially of a bare-die integrated circuit. In some embodiments, the integrated circuit includes or consists essentially of multiple active and/or passive devices that are fabricated on a common semiconductor substrate.

In other embodiments, power conductors 210, 220 may provide AC power, or power modulated at different frequencies and in these embodiments CEs 240 may be selected accordingly or may be omitted. In one embodiment, power conductors 210, 220 may provide a standard line voltage, for example about 120 VAC or about 240 VAC or about 277 VAC, for example at about 50 Hz or about 60 Hz. In some embodiments, CEs 240 may accommodate a plurality of input types, and thus be so-called “universal” CEs 240, while in other embodiments different CEs 240 may be required for different input types. The actual component or components of CEs 240 are not limiting to this invention; however, in preferred embodiments of this invention, the positioning of CEs 240 does not disrupt the LEE pitch. In another embodiment of this invention, the positioning of CEs 240 is independent of LEE pitch. As discussed herein, CEs 240 and LEEs 230 may be electrically coupled to conductive traces 260 using a variety of means, for example solder, conductive adhesive or ACA; however, the method of electrical coupling of CEs 140 and LEEs 230 is not a limitation of the present invention.

The terms and expressions employed herein are used as terms and expressions of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive. 

What is claimed is:
 1. A lighting system comprising: a first light panel comprising: a first substrate, first and second spaced-apart power conductors disposed on the first substrate, a plurality of first light-emitting elements disposed on the first substrate and electrically connected to the first and second power conductors, a first connector disposed on the first substrate and electrically connected to the first power conductor, and a second connector disposed on the first substrate and electrically connected to the second power conductor; a second light panel comprising: a second substrate, third and fourth spaced-apart power conductors disposed on the second substrate, a plurality of second light-emitting elements disposed on the second substrate and electrically connected to the third and fourth power conductors, a third connector disposed on the second substrate and electrically connected to the third power conductor, a fourth connector disposed on the second substrate and electrically connected to the fourth power conductor, a fifth connector disposed on the second substrate and electrically connected to the third power conductor, and a sixth connector disposed on the second substrate and electrically connected to the fourth power conductor; and a power distribution bus comprising: first and second power distribution lines, a seventh connector electrically connected to the first power distribution line, and an eighth connector electrically connected to the second power distribution line, wherein (i) the first connector is configured for direct mechanical contact and connection to the third connector, thereby electrically coupling the first power conductor to the third power conductor, (ii) the second connector is configured for direct mechanical contact and connection to the fourth connector, thereby electrically coupling the second power conductor to the fourth power conductor, (iii) the seventh connector is configured for connection to the fifth connector, thereby electrically coupling the third power conductor to the first power distribution line, and (iv) the eighth connector is configured for connection to the sixth connector, thereby electrically coupling the fourth power conductor to the second power distribution line.
 2. The lighting system of claim 1, wherein: the first substrate comprises a plurality of first conductive traces thereon, the plurality of first light-emitting elements are spaced apart and interconnected, via the plurality of first conductive traces, into one or more first light-emitting strings, and each first light-emitting string has (i) a first end electrically connected to the first power conductor and (ii) a second end electrically connected to the second power conductor.
 3. The lighting system of claim 2, wherein, when (i) the first connector is connected to the third connector and (ii) the second connector is connected to the fourth connector, over the first and second substrates the first and second light-emitting elements are spaced apart at a substantially constant first pitch in a first direction, the first pitch being maintained between the first and second substrates.
 4. The lighting system of claim 3, wherein, when (i) the first connector is connected to the third connector and (ii) the second connector is connected to the fourth connector, over the first and second substrates the first and second light-emitting elements are spaced apart at a substantially constant second pitch in a second direction different from the first direction, the second pitch being maintained between the first and second substrates.
 5. The lighting system of claim 4, wherein the first pitch and the second pitch are substantially equal.
 6. The lighting system of claim 2, further comprising one or more first control elements each configured to control current to one or more of the first light-emitting strings, wherein (i) the one or more first control elements are disposed on at least one of the first substrate or the second substrate, and (ii) the one or more first control elements are each electrically coupled to at least one first light-emitting string.
 7. The lighting system of claim 2, wherein the first substrate is separable, via a cut spanning the first and second power conductors and not crossing a first light-emitting string, into two partial substrates each comprising (i) one or more first light-emitting strings, and (ii) portions of the first and second power conductors configured to supply power to and thereby illuminate the one or more first light-emitting strings of the partial substrate.
 8. The lighting system of claim 1, wherein the first power conductor is disposed proximate a first edge of the first substrate.
 9. The lighting system of claim 8, wherein the first edge is folded to thereby increase an effective width of the first power conductor, whereby the first edge comprises two substantially planar sections folded at a crease therebetween.
 10. The lighting system of claim 1, further comprising a first frame element disposed at least partially on the first substrate.
 11. The lighting system of claim 10, wherein the first frame element (i) comprises a first electrically conductive element, and (ii) is configured to electrically couple the first electrically conductive element to the first power conductor, thereby decreasing an effective electrical resistivity of the first power conductor.
 12. The lighting system of claim 10, wherein (i) the first frame element comprises a first electrically conductive element, (ii) the first power conductor comprises a plurality of electrically discontinuous sections, and (iii) the first electrically conductive element is configured to electrically connect at least two electrically discontinuous sections of the first power conductor.
 13. The lighting system of claim 10, wherein the first frame element is flexible.
 14. The lighting system of claim 10, wherein the first frame element is positionable, whereby the first frame element maintains a deformed configuration in the absence of a deforming force.
 15. The lighting system of claim 1, wherein at least one of the first substrate or the second substrate is flexible.
 16. The lighting system of claim 1, further comprising an optic disposed over at least the first light panel.
 17. The lighting system of claim 16, wherein the optic comprises at least one of a lens, a diffuser, a refractive optic, a reflective optic, a Fresnel optic, a fabric, a translucent material panel, a graphic panel, or a membrane.
 18. The lighting system of claim 16, wherein a collective thickness of the first light panel and the optic is less than 500 mm.
 19. The lighting system of claim 16, wherein a collective thickness of the first light panel and the optic is between 1 times and 5 times a spacing between the first light-emitting elements.
 20. The lighting system of claim 16, further comprising at least one spacer, disposed between the first light panel and the optic, wherein the spacer positions the optic at a substantially fixed distance apart from the first light panel.
 21. The lighting system of claim 20, wherein the first light panel defines an opening therethrough proximate the spacer.
 22. The lighting system of claim 1, further comprising: a third light panel comprising: a third substrate, fifth and sixth spaced-apart power conductors disposed on the third substrate, a plurality of third light-emitting elements disposed on the third substrate and electrically connected to the fifth and sixth power conductors, a ninth connector electrically connected to the fifth power conductor, and a tenth connector electrically connected to the sixth power conductor; and a fourth light panel comprising: a fourth substrate, seventh and eighth spaced-apart power conductors disposed on the fourth substrate, a plurality of fourth light-emitting elements disposed on the fourth substrate and electrically connected to the seventh and eighth power conductors, a eleventh connector electrically connected to the seventh power conductor, and an twelfth connector electrically connected to the eighth power conductor, wherein (A) the eleventh connector is configured for connection to the ninth connector, thereby electrically coupling the fifth power conductor to the seventh power conductor, (D) the twelfth connector is configured for connection to the tenth connector, thereby electrically coupling the sixth power conductor to the eighth power conductor, and (E) when (i) the first connector is connected to the third connector, (ii) the second connector is connected to the fourth connector, (iii) the ninth connector is connected to the eleventh connector, (iv) the tenth connector is connected to the twelfth connector, (v) the first light panel is disposed adjacent to the third light panel, and (vi) the second light panel is disposed adjacent to the fourth light panel, the first, second, third, and fourth light-emitting elements are spaced apart at a substantially constant first pitch in a first direction over the first, second, third, and fourth substrates, the first pitch being maintained among the first, second, third, and fourth substrates.
 23. The lighting system of claim 22, wherein, when (i) the first connector is connected to the third connector, (ii) the second connector is connected to the fourth connector, (iii) the ninth connector is connected to the eleventh connector, (iv) the tenth connector is connected to the twelfth connector, (v) the first light panel is disposed adjacent to the third light panel, and (vi) the second light panel is disposed adjacent to the fourth light panel, the first, second, third, and fourth light-emitting elements are spaced apart at a substantially constant second pitch in a second direction over the first, second, third, and fourth substrates, the second pitch being maintained among the first, second, third, and fourth substrates.
 24. The lighting system of claim 23, wherein the first pitch and the second pitch are substantially equal.
 25. The lighting system of claim 1, further comprising a power supply electrically connected to the power distribution bus.
 26. The lighting system of claim 1, wherein the first light panel has a thickness in the range of 0.25 mm to 25 mm.
 27. The lighting system of claim 1, wherein the first light-emitting elements (i) comprise light-emitting diodes and (ii) emit substantially white light.
 28. The lighting system of claim 1, wherein the first light-emitting elements are arranged in an array comprising (i) a plurality of columns interconnected along a first direction, and (ii) a plurality of rows interconnected along a second direction different from the first direction.
 29. The lighting system of claim 28, wherein each column contains the same number of first light-emitting elements.
 30. The lighting system of claim 28, wherein each row contains the same number of first light-emitting elements.
 31. The lighting system of claim 1, further comprising (i) a first frame element disposed proximate a first edge of the first substrate, and (ii) a second frame element disposed proximate a second edge of the first substrate, the second edge being opposite the first edge, wherein (a) the first power conductor is disposed proximate the first edge of the first substrate, and (b) the second power conductor is disposed proximate the second edge of the first substrate.
 32. The lighting system of claim 31, wherein the first frame element (i) comprises a first electrically conductive element, and (ii) is configured to electrically couple the first electrically conductive element to the first power conductor, thereby decreasing an effective electrical resistivity of the first power conductor; and the second frame element (i) comprises a second electrically conductive element, and (ii) is configured to electrically couple the second electrically conductive element to the second power conductor, thereby decreasing an effective electrical resistivity of the second power conductor.
 33. The lighting system of claim 1, wherein the plurality of first light-emitting elements comprises at least two groups of LEEs, each group having a different electrical and/or optical characteristic.
 34. The lighting system of claim 33, wherein each group has a different optical characteristic, the optical characteristic comprising at least one of color, color temperature, intensity, efficiency, color rendering index, or spectral light distribution.
 35. The lighting system of claim 1, wherein, when the first connector is connected to the third connector, and the second connector is connected to the fourth connector: a portion of the first substrate overlaps a portion of the second substrate; or a portion of the second substrate overlaps a portion of the first substrate.
 36. The lighting system of claim 1, wherein, when the seventh connector is connected to the fifth connector, and the eighth connector is connected to the sixth connector: a portion of the second substrate overlaps a portion of the power distribution bus; or a portion of the power distribution bus overlaps a portion of the second substrate.
 37. The lighting system of claim 1, wherein: the first connector is a male connector, and the second connector is a female connector; or the first connector is a female connector, and the second connector is a male connector.
 38. The lighting system of claim 1, wherein: the third connector is a male connector, and the fourth connector is a female connector; or the third connector is a female connector, and the fourth connector is a male connector.
 39. The lighting system of claim 1, wherein: the fifth connector is a male connector, and the sixth connector is a female connector; or the fifth connector is a female connector, and the sixth connector is a male connector.
 40. The lighting system of claim 1, wherein: the seventh connector is a male connector, and the eighth connector is a female connector; or the seventh connector is a female connector, and the eighth connector is a male connector.
 41. The lighting system of claim 1, wherein the first and second power conductors are disposed on and extend along opposing edges of the first substrate.
 42. The lighting system of claim 1, wherein the third and fourth power conductors are disposed on and extend along opposing edges of the second substrate.
 43. The lighting system of claim 1, wherein at least one of the first connector or the second connector is disposed on a protruding tab defined by the first substrate.
 44. The lighting system of claim 1, wherein at least one of the third connector, the fourth connector, the fifth connector, or the sixth connector is disposed on a protruding tab defined by the second substrate.
 45. A lighting system comprising: a first light panel comprising: a first substrate, first and second spaced-apart power conductors disposed on the first substrate, a plurality of first light-emitting elements disposed on the first substrate and electrically connected to the first and second power conductors, a first connector electrically connected to the first power conductor, and a second connector electrically connected to the second power conductor; a second light panel comprising: a second substrate, third and fourth spaced-apart power conductors disposed on the second substrate, a plurality of second light-emitting elements disposed on the second substrate and electrically connected to the third and fourth power conductors, a third connector electrically connected to the third power conductor, a fourth connector electrically connected to the fourth power conductor, a fifth connector electrically connected to the third power conductor, and a sixth connector electrically connected to the fourth power conductor; and a power distribution bus comprising: first and second power distribution lines, a seventh connector electrically connected to the first power distribution line, and an eighth connector electrically connected to the second power distribution line, wherein (i) the first connector is configured for direct mechanical contact and connection to the third connector, thereby electrically coupling the first power conductor to the third power conductor, (ii) the second connector is configured for direct mechanical contact and connection to the fourth connector, thereby electrically coupling the second power conductor to the fourth power conductor, (iii) the seventh connector is configured for connection to the fifth connector, thereby electrically coupling the third power conductor to the first power distribution line, and (iv) the eighth connector is configured for connection to the sixth connector, thereby electrically coupling the fourth power conductor to the second power distribution line, and wherein, when the first connector is connected to the third connector, and the second connector is connected to the fourth connector, (a) a portion of the first substrate overlaps a portion of the second substrate, or (b) a portion of the second substrate overlaps a portion of the first substrate. 